Ascending Aortic Aneurysm EnlargementTITAN:SvSNCT03536312
Treatment in Thoracic Aortic Aneurysm: Surgery vs Surveillance
A study testing Thoracic Aortic Surgery in people with Ascending Aortic Aneurysm Enlargement and Ascending Aorta Aneurysm, run by Ottawa Heart Institute Research Corporation at 31 sites in 3 countries.
Trial summary
The ascending aorta conducts blood from the heart to the rest of the body. The ascending aorta can become enlarged, and the risk of tearing and rupturing becomes higher with larger aorta. When the ascending aorta tears or ruptures, the risk dying is high even if surgery is done as soon as possible. Read more about this study
- Who is it for?
- Ages 18 to 79 years
- Conditions the study is for
- Ascending Aortic Aneurysm Enlargement, Ascending Aorta Aneurysm
- What is being tested?
- Thoracic Aortic Surgery
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 610 participants
- Where
- 31 sitesin 3 countries
- Study dates
- 1 Sep 2018to 31 May 2035
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 79 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients between the age of 18 and 79 inclusive.
- Ascending aortic aneurysm between 5.0cm and 5.4cm in maximal diameter as measured by CT with contrast.
- Patients with ascending aortic aneurysm with a diameter of 4.5 cm - 4.9 cm will be observed with serial CT, and will be considered for enrollment into the trial once the aneurysm reaches 5.0 cm.
Who cannot join
- Patients who refused to be randomized
- Patients with symptomatic attributable to ascending aortic aneurysms
- Patients who are unable to provide informed consents
- Patients who are unable to attend for regular follow-up/ remain compliant with protocol
- Previous cardiac surgery
- Patients whose primary indication for cardiac surgery is non-AsAA related
Show all 22Show fewer
- Known AsAA expansion rate exceeding 0.5 cm/year during the past 5 years
- Arch aneurysms with no ascending aorta involvement (no aneurysmal segments before the innominate artery)
- Ascending aortic and arch aneurysm with descending thoracic aorta involvement
- Patients with known connective tissue disease (E.g. Marfan syndrome, Loey-Dietz syndrome, Turner syndrome etc) syndrome, etc.)
- Patients with possible genetic aortopathies (eg known family history of aortic aneurysms/premature aortic dissections/ruptures)
- Patients with inflammatory arteritis (e.g. takayasu's arteritis, syphilitic arteritis, etc.)
- Female patients who are pregnant or planning to become pregnant
- Patients who have a history or presence of a medical condition or disease or psychiatric condition that in the investigator's assessment would render the subject ineligible for study participation.
- Patients who, in the opinion of the investigator, are deemed unfit for surgery for reasons that may include:
- Severe pulmonary disease
- Cr = 250umol/L
- Child Pugh Class B or C
- NYHA III or IV
- MI within the last 6 months
- Major surgical procedure or angioplasty within 3 months
- Expected survival less than 5 years because of other disease (e.g. invasive cancer)
Trial locations and contacts
31 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
31 sites in 3 countries
United States16 sites, 16 recruiting
- Recruiting
University of Michigan
Ann Arbor, Michigan, 48109
Himanshu Patel, MD
Bo Yang, MD
- Recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02114
Arminder Jassar, MD
Thoralf Sundt, MD
- Recruiting
Beth Israel Deaconess Medical Center
Boston, Massachusetts, 02215
Jenifer Kaufman, 617-632-8956, jmkaufma@bidmc.harvard.edu
Brett Carroll, MD
- Recruiting
MUSC Health University Medical Center
Charleston, South Carolina, 29425
Hannah Culpepper, 843-792-7244, culpepph@musc.edu
Sanford Zeigler, MD
- Recruiting
University Hospitals Cleveland
Cleveland, Ohio, 44106
Nisreen Zueiter, 216-844-1000, nisreen.zueiter@UHhospitals.org
Cristian Baeza, MD
- Recruiting
Ohio State University Medical Center
Columbus, Ohio, 43210
Jovan Bovinovski, MD
- Recruiting
Duke University
Durham, North Carolina, 27705
G. Chad Hughes, MD
- Recruiting
University of Texas Health Science Centre
Houston, Texas, 77030
Anthony Estrera, MD
Charles Miller, MD
- Recruiting
University of Iowa
Iowa City, Iowa, 52242
Gawain J Williams, 319-384-1500, gawain-williams@uiowa.edu
Mohammad Bashir, MD
- Recruiting
Icahn School of Medicine at Mount Sinai
New York, New York, 10029
Ismail El-Hamamsy, MD
- Recruiting
The Trustees of the University of Pennsylvania
Philadelphia, Pennsylvania, 19104
Nimesh Desai, MD
Wilson Szeto, MD
- Recruiting
Baylor Scott & White Research Institute
Plano, Texas, 75093
William Brinkman, MD
- Recruiting
The Valley Hospital, Inc
Ridgewood, New Jersey, 07652
Juan Grau, MD
Jabagi Habib, MD
- Recruiting
Mayo Clinic
Rochester, Minnesota, 55905
Disrud Levi, 507-284-2511, Disrud.Levi@mayo.edu
Gabor Bagameri, MD
- Recruiting
University of California at San Francisco Medical Center
San Francisco, California, 94121
Elaine Tseng, MD
- Recruiting
Washington University School of Medicine
St Louis, Missouri, 63110
Allison Schuck, 314-362-5000, aschuck@wustl.edu
Puja Kachroo, MD
Canada14 sites, 12 recruiting
- Active, not recruiting
University of Calgary
Calgary, Alberta, T2N 2T9
- Recruiting
Mazankowski Alberta Heart Institute
Edmonton, Alberta, T6G 0M9
Nasim Boroumand, 780-407-2667, nasim.boroumand@ahs.ca
Michael Moon, MD
- Recruiting
Health Sciences North
Greater Sudbury, Ontario
Rony Atoui, MD
Michael Conlon, PhD
- Recruiting
Nova Scotia Health Authority
Halifax, Nova Scotia, B3S 0H6
Cynthia Ukeoma, 902-473-2847, Cynthia.Ukeoma@nshealth.ca
Christine Herman, MD
- Active, not recruiting
Hamilton General Hospital
Hamilton, Ontario
- Recruiting
London Health Sciences Centre
London, Ontario, N6A 5A5
Michael Chu, MD
- Recruiting
Montreal Heart Institute
Montreal, Quebec, H1T 1C8
Philippe Demers, MD
Philippe Demers, MD
- Recruiting
McGill University Health Centre
Montreal, Quebec, H3H2R9
Kevin Lachapelle, MD
- Recruiting
University of Ottawa Heart Institute
Ottawa, Ontario, K1Y 4W7
Munir Boodhwani, MD, 613-696-7237, MBoodhwani@ottawaheart.ca
Khatira Mehdiyeva, 613-696-7000, kmehdiyeva@ottawaheart.ca
- Recruiting
Institut universitaire de cardiologie et de pneumologie de Québec
Québec, Quebec, G1V 4G5
François Dagenais, MD
- Recruiting
Horizon Health Network
Saint John, New Brunswick, E2L 4L2
Zlatko Pozeg, MD
- Recruiting
Newfoundland Health Services
St. John's, Newfoundland and Labrador, A1E 5T2
Shianne Beson, 709-777-1950, Shianne.beson@nlhealthservices.ca
David Glineur, MD
- Not yet recruiting
St. Michael's Hospital
Toronto, Ontario, M5B 1W8
Mark Peterson, MD
- Recruiting
Toronto General Hospital
Toronto, Ontario
Maral Ouzounian, MD
Sweden1 site, 1 recruiting
- Recruiting
Skåne University Hospital
Malmö, Skåne County, 214 28
Louise Thelaus, +46 40 33 10 00, louise.thelaus@med.lu.se
Igor Zindovic, MD
About this study
Official title: Treatment in Thoracic Aortic Aneurysm: Surgery vs Surveillance (TITAN:SvS)
The ascending aorta conducts blood from the heart to the rest of the body. The ascending aorta can become enlarged, and the risk of tearing and rupturing becomes higher with larger aorta. When the ascending aorta tears or ruptures, the risk dying is high even if surgery is done as soon as possible. Traditionally, when the ascending aorta gets above 5.5 cm, surgery is recommended to replace the aorta. However, this threshold is based relatively weak evidence, and sometimes patients with smaller aorta can tear or rupture. On the other hand, surgery carries its own risk as well. Since there are risk of waiting or doing surgery, there is currently no great support for either approach for patients with a smaller aorta. In the TITAN SvS trial, patients with an ascending aorta between 5.0 to 5.5 cm is assigned by chance to the early surgery group, in which they will undergo replacement of aorta, or the surveillance group, in which they will be closely monitored. The chance of dying or suffer tearing or rupture of aorta between the two groups will be compared. The result of the trial will guide future practice for patients with enlarged ascending aorta.
This is a prospective, multi-centre randomized control trial that compares the all-cause mortality, aneurysm-related aortic events, rate of stroke, and quality of life for those patients undergoing early elective ascending aortic surgery to those patients undergoing surveillance. Patients referred for an ascending aortic aneurysm that meets the inclusion criteria will be randomized to the early elective surgery group or the surveillance group. Recruitment will end when the desired sample size is reached, and the patients will be followed for a minimum 2-year period. The primary objective of the trial is to compare the composite outcome of the all-cause mortality and incidence of acute aortic events between surveillance and elective ascending aortic surgery for patients with degenerative or bicuspid valve-related ascending aortic aneurysm after 2 years of follow up. The hypothesis is that the early surgery group will have a significantly lower all-cause mortality and incidence of acute aortic events at 2 years of follow up compare to the surveillance group. The result of this trial will provide evidence based guidance in the appropriate management of ascending aortic aneurysm based on the size criteria, and establish a large database for future investigations.
Read the detailed description
All patients referred electively to a participating investigator for the evaluation of their ascending aortic aneurysm will be screened for study eligibility. Patients between the age of 18 and 79 with an asymptomatic ascending aortic aneurysm between 5.0 cm and 5.4 cm in maximal diameter are entered into the randomization study. Patients with ascending aortic aneurysm with a diameter of 4.5 cm - 4.9 cm will be observed with serial CT, and will be considered for enrollment into the trial once the aneurysm reaches 5.0 cm.
When the patient is first assessed in clinic, a pre-randomization evaluation will be completed. Baseline information of the patient, including demographics, past medical history, family history, medications, smoking habits, and the characteristics of the aneurysm, is collected. Measurements including weight, height, heart rate, blood pressure in both arms, is recorded. Basic blood work, including hemoglobin, white cell count, platelets, electrolytes, creatinine, random blood sugar, HbA1c, and cholesterol profile is taken for analysis. An electrocardiograph, chest X-ray, and a CT scan from the surgeon's institution is also obtained. SF-36, the quality of life questionnaire, will be completed by the patient. Those patients that are suitable for the trial based on inclusion and exclusion criteria will then be randomized en-site through a computer-generated randomization program.
For the patients randomized to elective surgery group, the surgery is scheduled within 10-12 weeks of randomization. In the interim, the patient will be placed on maximal medical therapy for their aneurysm, including beta-blocker, statin, and blood pressure control, and the doses of these medication will be individualized based on each patient's own physiological response. The types of surgery (ascending aortic replacement, Bentall procedure, valve-sparing root replacement, etc.) will be at the discretion of the surgeon. The details of the surgery and the patient's course of postoperative hospital stay is recorded. The patient will be managed postoperatively according to routine hospital care. After discharge, patients will be seen at 1 months for their routine postoperative follow up, then annually counting from their index clinic visit before the surgery. At the first postoperative clinic visit, weight, height, heart rate, blood pressure in both arms, is recorded. Basic blood work, including hemoglobin, white cell count, platelets, electrolytes, creatinine is taken for analysis. An electrocardiograph and chest X-ray will be obtained. All subsequent clinic visits can be done in person or by phone conducted by a study coordinator. A CT scan will be obtained at all subsequent clinic visits. Mortality status and occurrence of acute aortic event or stroke in the previous year will be assessed at every annual clinic visit. Quality of life assessment by SF-36 questionnaire will be completed by the patient in person or by phone at 1 year and 2 years follow-up. Annual follow-up will continue until either the patient dies or the trial ends. Patients who are randomized to the surveillance group will be placed on maximal medical therapy for their aneurysm, including beta-blocker, statin, and blood pressure control. The doses of these medication will be individualized based on each patient's own physiological response. The patients will undergo a CT scan of the chest at the first clinic visit then annually for the duration of the study. All CTs will be uploaded to a core CT imaging lab where the image will be reviewed by a Radiologist. If the aneurysm grows beyond 5.5 cm or the patient develop symptoms, the surgeon will consider the patient for surgery. At all clinic visits, in addition to CT, weight, height, heart rate, blood pressure in both arms, an electrocardiograph, and a chest X-ray will be obtained. The surveillance visits continue until either the patient dies, the trial ends, or surgery is considered. If the patient is no longer considered a suitable candidate for surgery or refuse surgery, follow-up will continue, and the patient will no longer be a part of the trial and will only be registered in the side arm.
- Being tested
- Thoracic Aortic Surgery
- Keywords
- Ascending Aorta Aneurysm, Aneurysm, Randomized Control Trial
- Medical subject headings
- Aneurysm, Ascending Aorta, Aneurysm
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Thoracic Aortic SurgeryProcedure or surgery
Thoracic aortic surgery to treat thoracic aortic aneurysm
| Study group | Role | What they receive |
|---|---|---|
| Surveillance Arm | No intervention | Patients in the Non-Operative Registry will be followed in clinic annually with a CT scan to monitor the status of their ascending aortic aneurysm, until the end of the study, the occurrence of an aortic event, or death. |
| Surgery/Treatment Arm | Other | Patients in the Operative Registry will have thoracic aortic surgery Receives: Procedure: Thoracic Aortic Surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
All-cause mortality and incidence of acute aortic events in both surveillance and elective ascending aortic surgery groups for patients with degenerative or bicuspid valve-related ascending aortic aneurysm after 2 years of follow up.
At 2 years follow up, number of patients in surveillance versus treatment group suffering from mortality or acute aortic dissection
Measured: 2 years
Secondary outcomes (7)
Intraoperative mortality and 30 day mortality of ascending aortic aneurysm repair
Document death during surgery or within 30 days post surgery
Measured: 30 days from surgery
Incidence of need for elective ascending aortic aneurysm repair in the surveillance group
How many patients on the surveillance arm of the trial need to have surgery prior to the end of trial surveillance
Measured: 2 years
Non aneurysm related death
How many patients in either surgical or surveillance arm have a non aneurysm related death
Measured: 2 years
Aneurysm related death
How many patients in either the surveillance or surgical arm have an aneurysm related death
Measured: 2 years
Incidence of cerebrovascular accidents (CVA)
How many patients have a CVA on the surgical or surveillance arm
Measured: 2 years
Annual growth rate in diameter of ascending aortic aneurysm in the surveillance group
Prospective assessment of the rate of growth in mm/yr of moderate sized ascending aortic aneurysms
Measured: 2 years
Quality of life at 1 year and 2 years for both groups
Patients will fill in questionnaires to assess impact of surveillance strategy versus surgery on quality of life
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 May 2018
- Study start1 Sep 2018
- Primary completion31 May 2035 (estimated)
- Study completion31 May 2035 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Ascending Aortic Aneurysm EnlargementStudies of the same condition, open and under way.
- More trials run by Ottawa Heart Institute Research CorporationThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Patients between the age of 18 and 79 with an asymptomatic ascending aortic aneurysm between 5.0 cm and 5.4 cm in maximal diameter are entered into the randomization study.
- Masking
- None (open label)
- Enrolment
- 610 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ottawa Heart Institute Research Corporation
- Sponsor type
- University, hospital or other
- Collaborators
- University of Calgary, University Health Network, Toronto, Institut universitaire de cardiologie et de pneumologie de Québec, University Laval, Hamilton General Hospital, Montreal Heart Institute, University of Pennsylvania, Massachusetts General Hospital, McGill University, University of Michigan, Ohio State University, Icahn School of Medicine at Mount Sinai, Washington University School of Medicine, University Hospitals Cleveland Medical Center, University of Alberta, Mayo Clinic, Medical University of South Carolina, Nova Scotia Health Authority, London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's, Horizon Health Network, The University of Texas Health Science Center, Houston, San Francisco Veterans Affairs Medical Center, Health Sciences North Research Institute, Baylor Scott and White Health, Duke Clinical Research Institute, Oxford Diabetes Trials Unit, The Valley Hospital, Beth Israel Deaconess Medical Center, Newfoundland Health Services, University of Iowa, Skang University Hospital
- Responsible party
- Sponsor
- Investigators
- Munir Boodhwani, MD, Principal investigator, Ottawa Heart Institute Research CorporationJehangir Appoo, MD, Principal investigator, University of Calgary
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03536312
- Sponsor's protocol ID
- 20180007-01H
- Acronym
- TITAN:SvS
- Status last verified
- Oct 2026
- First submitted
- 18 Apr 2018
- Last updated
- 2 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Dagher O, Appoo JJ, Herget E, Atoui R, Baeza C, Brinkman W, Bozinovski J, Chu MWA, Dagenais F, Demers P, Desai N, El-Hamamsy I, Estrera A, Grau JB, Hughes GC, Jassar A, Kachroo P, Lachapelle K, Ouzounian M, Patel HJ, Pozeg Z, Tseng E, Whitlock R, Guo MH, Boodhwani M. Impact of nondiameter aortic indices on surgical eligibility: Results from the Treatment in Thoracic Aortic Aneurysm: Surgery Versus Surveillance (TITAN: SvS) randomized controlled trial. J Thorac Cardiovasc Surg. 2025 Mar;169(3):857-865.e1. doi: 10.1016/j.jtcvs.2024.04.010. Epub 2024 Apr 29.
PubMed 38692478Guo MH, Appoo JJ, Wells GA, Chu M, Ouzounian M, Fortier J, Boodhwani M. Protocol for a randomised controlled trial for Treatment in Thoracic Aortic Aneurysm: Surgery versus Surveillance (TITAN: SvS). BMJ Open. 2021 May 26;11(5):e052070. doi: 10.1136/bmjopen-2021-052070.
PubMed 34039580
Study at a glance
From the registry record, last updated by the sponsor on 2 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Treatment in Thoracic Aortic Aneurysm: Surgery vs Surveillance (TITAN:SvS)
- ClinicalTrials.gov ID
- NCT03536312
- Acronym / sponsor ID
- TITAN:SvS / 20180007-01H
- Keywords
- Ascending Aorta Aneurysm, Aneurysm, Randomized Control Trial
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 610 participants (estimated)
- Lead sponsor
- Ottawa Heart Institute Research CorporationUniversity, hospital or other
- Collaborators
- University of Calgary, University Health Network, Toronto, Institut universitaire de cardiologie et de pneumologie de Québec, University Laval, Hamilton General Hospital, Montreal Heart Institute, University of Pennsylvania, Massachusetts General Hospital, McGill University, University of Michigan, Ohio State University, Icahn School of Medicine at Mount Sinai, Washington University School of Medicine, University Hospitals Cleveland Medical Center, University of Alberta, Mayo Clinic, Medical University of South Carolina, Nova Scotia Health Authority, London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's, Horizon Health Network, The University of Texas Health Science Center, Houston, San Francisco Veterans Affairs Medical Center, Health Sciences North Research Institute, Baylor Scott and White Health, Duke Clinical Research Institute, Oxford Diabetes Trials Unit, The Valley Hospital, Beth Israel Deaconess Medical Center, Newfoundland Health Services, University of Iowa, Skang University Hospital
- Study start
- 1 Sep 2018 (actual)
- Primary completion
- 31 May 2035 (estimated)
- Study completion
- 31 May 2035 (estimated)
- First posted
- 24 May 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The ascending aorta conducts blood from the heart to the rest of the body. The ascending aorta can become enlarged, and the risk of tearing and rupturing becomes higher with larger aorta. When the ascending aorta tears or ruptures, the risk dying is high even if surgery is done as soon as possible. Traditionally, when the ascending aorta gets above 5.5 cm, surgery is recommended to replace the aorta. However, this threshold is based relatively weak evidence, and sometimes patients with smaller aorta can tear or rupture. On the other hand, surgery carries its own risk as well. Since there are risk of waiting or doing surgery, there is currently no great support for either approach for patients with a smaller aorta. In the TITAN SvS trial, patients with an ascending aorta between 5.0 to 5.5 cm is assigned by chance to the early surgery group, in which they will undergo replacement of aorta, or the surveillance group, in which they will be closely monitored. The chance of dying or suffer tearing or rupture of aorta between the two groups will be compared. The result of the trial will guide future practice for patients with enlarged ascending aorta.
This is a prospective, multi-centre randomized control trial that compares the all-cause mortality, aneurysm-related aortic events, rate of stroke, and quality of life for those patients undergoing early elective ascending aortic surgery to those patients undergoing surveillance. Patients referred for an ascending aortic aneurysm that meets the inclusion criteria will be randomized to the early elective surgery group or the surveillance group. Recruitment will end when the desired sample size is reached, and the patients will be followed for a minimum 2-year period. The primary objective of the trial is to compare the composite outcome of the all-cause mortality and incidence of acute aortic events between surveillance and elective ascending aortic surgery for patients with degenerative or bicuspid valve-related ascending aortic aneurysm after 2 years of follow up. The hypothesis is that the early surgery group will have a significantly lower all-cause mortality and incidence of acute aortic events at 2 years of follow up compare to the surveillance group. The result of this trial will provide evidence based guidance in the appropriate management of ascending aortic aneurysm based on the size criteria, and establish a large database for future investigations.
Detailed description
All patients referred electively to a participating investigator for the evaluation of their ascending aortic aneurysm will be screened for study eligibility. Patients between the age of 18 and 79 with an asymptomatic ascending aortic aneurysm between 5.0 cm and 5.4 cm in maximal diameter are entered into the randomization study. Patients with ascending aortic aneurysm with a diameter of 4.5 cm - 4.9 cm will be observed with serial CT, and will be considered for enrollment into the trial once the aneurysm reaches 5.0 cm.
When the patient is first assessed in clinic, a pre-randomization evaluation will be completed. Baseline information of the patient, including demographics, past medical history, family history, medications, smoking habits, and the characteristics of the aneurysm, is collected. Measurements including weight, height, heart rate, blood pressure in both arms, is recorded. Basic blood work, including hemoglobin, white cell count, platelets, electrolytes, creatinine, random blood sugar, HbA1c, and cholesterol profile is taken for analysis. An electrocardiograph, chest X-ray, and a CT scan from the surgeon's institution is also obtained. SF-36, the quality of life questionnaire, will be completed by the patient. Those patients that are suitable for the trial based on inclusion and exclusion criteria will then be randomized en-site through a computer-generated randomization program.
For the patients randomized to elective surgery group, the surgery is scheduled within 10-12 weeks of randomization. In the interim, the patient will be placed on maximal medical therapy for their aneurysm, including beta-blocker, statin, and blood pressure control, and the doses of these medication will be individualized based on each patient's own physiological response. The types of surgery (ascending aortic replacement, Bentall procedure, valve-sparing root replacement, etc.) will be at the discretion of the surgeon. The details of the surgery and the patient's course of postoperative hospital stay is recorded. The patient will be managed postoperatively according to routine hospital care. After discharge, patients will be seen at 1 months for their routine postoperative follow up, then annually counting from their index clinic visit before the surgery. At the first postoperative clinic visit, weight, height, heart rate, blood pressure in both arms, is recorded. Basic blood work, including hemoglobin, white cell count, platelets, electrolytes, creatinine is taken for analysis. An electrocardiograph and chest X-ray will be obtained. All subsequent clinic visits can be done in person or by phone conducted by a study coordinator. A CT scan will be obtained at all subsequent clinic visits. Mortality status and occurrence of acute aortic event or stroke in the previous year will be assessed at every annual clinic visit. Quality of life assessment by SF-36 questionnaire will be completed by the patient in person or by phone at 1 year and 2 years follow-up. Annual follow-up will continue until either the patient dies or the trial ends. Patients who are randomized to the surveillance group will be placed on maximal medical therapy for their aneurysm, including beta-blocker, statin, and blood pressure control. The doses of these medication will be individualized based on each patient's own physiological response. The patients will undergo a CT scan of the chest at the first clinic visit then annually for the duration of the study. All CTs will be uploaded to a core CT imaging lab where the image will be reviewed by a Radiologist. If the aneurysm grows beyond 5.5 cm or the patient develop symptoms, the surgeon will consider the patient for surgery. At all clinic visits, in addition to CT, weight, height, heart rate, blood pressure in both arms, an electrocardiograph, and a chest X-ray will be obtained. The surveillance visits continue until either the patient dies, the trial ends, or surgery is considered. If the patient is no longer considered a suitable candidate for surgery or refuse surgery, follow-up will continue, and the patient will no longer be a part of the trial and will only be registered in the side arm.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Patients between the age of 18 and 79 with an asymptomatic ascending aortic aneurysm between 5.0 cm and 5.4 cm in maximal diameter are entered into the randomization study.
| Arm | Type | Receives |
|---|---|---|
| Surveillance Arm | No intervention | –Patients in the Non-Operative Registry will be followed in clinic annually with a CT scan to monitor the status of their ascending aortic aneurysm, until the end of the study, the occurrence of an aortic event, or death. |
| Surgery/Treatment Arm | Other | Procedure: Thoracic Aortic SurgeryPatients in the Operative Registry will have thoracic aortic surgery |
Who may qualify
- Ages
- 18 to 79 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients between the age of 18 and 79 inclusive.
- Ascending aortic aneurysm between 5.0cm and 5.4cm in maximal diameter as measured by CT with contrast.
- Patients with ascending aortic aneurysm with a diameter of 4.5 cm - 4.9 cm will be observed with serial CT, and will be considered for enrollment into the trial once the aneurysm reaches 5.0 cm.
Key exclusion criteria (22 listed)
- Patients who refused to be randomized
- Patients with symptomatic attributable to ascending aortic aneurysms
- Patients who are unable to provide informed consents
- Patients who are unable to attend for regular follow-up/ remain compliant with protocol
- Previous cardiac surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Thoracic Aortic SurgeryThoracic aortic surgery to treat thoracic aortic aneurysm | Procedure or surgery | Surgery/Treatment Arm |
Primary outcome
All-cause mortality and incidence of acute aortic events in both surveillance and elective ascending aortic surgery groups for patients with degenerative or bicuspid valve-related ascending aortic aneurysm after 2 years of follow up.
Time frame: 2 years
At 2 years follow up, number of patients in surveillance versus treatment group suffering from mortality or acute aortic dissection
7 secondary outcomes
Intraoperative mortality and 30 day mortality of ascending aortic aneurysm repair
Time frame: 30 days from surgery
Incidence of need for elective ascending aortic aneurysm repair in the surveillance group
Time frame: 2 years
Non aneurysm related death
Time frame: 2 years
Aneurysm related death
Time frame: 2 years
Incidence of cerebrovascular accidents (CVA)
Time frame: 2 years
Annual growth rate in diameter of ascending aortic aneurysm in the surveillance group
Time frame: 2 years
Quality of life at 1 year and 2 years for both groups
Time frame: 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Nov 2026.
- Derived from this study: PubMed 38692478Dagher O, Appoo JJ, Herget E, Atoui R, Baeza C, Brinkman W, Bozinovski J, Chu MWA, Dagenais F, Demers P, Desai N, El-Hamamsy I, Estrera A, Grau JB, Hughes GC, Jassar A, Kachroo P, Lachapelle K, Ouzounian M, Patel HJ, Pozeg Z, Tseng E, Whitlock R, Guo MH, Boodhwani M. Impact of nondiameter aortic indices on surgical eligibility: Results from the Treatment in Thoracic Aortic Aneurysm: Surgery Versus Surveillance (TITAN: SvS) randomized controlled trial. J Thorac Cardiovasc Surg. 2025 Mar;169(3):857-865.e1. doi: 10.1016/j.jtcvs.2024.04.010. Epub 2024 Apr 29.
- Derived from this study: PubMed 34039580Guo MH, Appoo JJ, Wells GA, Chu M, Ouzounian M, Fortier J, Boodhwani M. Protocol for a randomised controlled trial for Treatment in Thoracic Aortic Aneurysm: Surgery versus Surveillance (TITAN: SvS). BMJ Open. 2021 May 26;11(5):e052070. doi: 10.1136/bmjopen-2021-052070.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Munir Boodhwani, MD principal investigator
Ottawa Heart Institute Research Corporation
Jehangir Appoo, MD principal investigator
University of Calgary
31 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Thoracic Aortic Surgery in people with Ascending Aortic Aneurysm Enlargement and Ascending Aorta Aneurysm, run by Ottawa Heart Institute Research Corporation at 31 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 31 sites in United States, Canada, Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Khatira Mehdiyeva (613-696-7000, kmehdiyeva@ottawaheart.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
All-cause mortality and incidence of acute aortic events in both surveillance and elective ascending aortic surgery groups for patients with degenerative or bicuspid valve-related ascending aortic aneurysm after 2 years of follow up. (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03536312, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Nov 2026.