Long Term Follow Up for CTSN Mitral Valve Repair Studies

This study is a continuation of two CTSN randomized trials --- the Severe Ischemic Mitral
Regurgitation (SMR) Trial (NCT00807040) and the Moderate Ischemic Mitral regurgitation (MMR)
Trial (NCT00806988) --- for the purpose of assessing the long-term outcomes of the index
surgical therapies. Key clinical outcomes will be collected utilizing electronic medical
records, patient and/or family input, public records, and healthcare- and vital
status-related databases. Extended follow-up data will be obtained on up to 199 SMR and 270
MMR trial participants, who were alive at their 2-year follow-up evaluation. Patients will be
followed for a minimum of 5 years and up to 10 years after randomization (the time of index
surgical procedure). This follow-up data collection will be conducted by the Cardiothoracic
Surgical Trials Network (CTSN) primarily utilizing the minimal PHI necessary to link data
obtained from the MMR and SMR trials to other healthcare- and/or vital status-related
databases.

Because the design of surgical trials for ischemic mitral regurgitation that would use
mortality as a primary endpoint requires the enrollment of thousands of patients, the
selected primary endpoint for the CTSN SMR and MMR trials was an echocardiographic measure of
left ventricular remodeling. Secondary endpoints included, among others, survival, adverse
events, readmissions and costs over a 2-year period. The SMR trial showed no difference in
left ventricular reverse remodeling, but the rate of moderate or severe mitral regurgitation
recurrence was significantly higher with mitral valve repair, resulting in more heart
failure-related adverse events and cardiovascular admissions. Longer-term follow-up will be
critical to assess whether this observed trend amongst SMR patients will continue and whether
a survival difference will manifest over time. In moderate ischemic mitral regurgitation,
mitral valve repair provided a more durable correction of mitral regurgitation than coronary
artery bypass grafting (CABG) alone, but repair did not improve survival or reduce overall
adverse events or readmissions, and was associated with an early hazard of neurological and
supraventricular arrhythmic events. Longer-term follow-up of MMR patients will provide
insights into whether the higher degree of recurrent mitral regurgitation with CABG alone
will be associated with differences in adverse events, readmissions and survival.
Additionally, the benefits of alternative surgical treatments for ischemic mitral
regurgitation, which have differential upfront risks and costs, will likely extend beyond 2
years. Cost-effectiveness analysis will delineate the long-term cost-benefit trade-offs
between mitral valve repair versus replacement for SMR, and of CABG with repair versus CABG
alone for MMR, which should inform surgical decision making, and examine how differences in
life expectancy and risk profiles of different patient groups affect cost-effectiveness over
time. This extended follow-up should provide important clinical and health policy insights.

Inclusion Criteria:

- Randomized patients in the MMR and SMR trials who were still alive at 2 years after
the index cardiac surgical intervention

Exclusion Criteria:

- Patients participating in the MMR and SMR trials who withdrew consent prior to the
2-year follow-up evaluation