Late outcomes
Clinical follow-up was complete for 302(87.5%) patients of the whole cohort (sternotomy: 75.8% versus MIVT: 92.0%, p<0.001). Median follow-up duration was 3.1(IQR 4.2)y, and significantly longer in the sternotomy group (sternotomy: 6.5(IQR 6)y versus MIVT: 2.5(IQR 4.3)y, p<0.001). The cumulative patient follow-up time was 962 patient/years.
Kaplan-Meier analysis showed no significant survival difference between the groups (p=0.472)(Figure 2). At last follow-up, sternotomy patients showed a higher NYHA class (p=0.015) and appeared to develop more frequently atrial fibrillation (Sternotomy: 3.8% vs. MIVT: 15.7%, p=0.002).
Echocardiographic assessment of MV function at last follow-up showed a similar quality of MV repair for the 2 groups, in terms of freedom from regurgitation(figure 3) as well as transmitral gradient (mean gradient: sternotomy 4.0(2.0) mmHg versus MIVT 4.0 (2.0) mmHg, p=0.810); max gradient: sternotomy 10.0(6.8) mmHg versus MIVT 10.0(5.4) mmHg, p=0.957).
Late reoperation for recurrent MV dysfunction was necessary in 8(8.6%) sternotomy patients vs. 11(4.4%) MIVT patients (p=0.130), revealing a comparable freedom from MV-related reoperation of 90.8±3.6% and 90.8±3.6% in the sternotomy group versus 93.9±2.0% and 90.7±3.0% in the MIVT group at respectively 3 and 5 years (logrank p=0.529)(Figure 4).