Organic vs. Functional Mitral Regurgitation in Patients Undergoing Transcatheter Aoric Valve Implantation for Severe Aortic Stenosis

Introduction: Many patients undergoing Transcatheter Aortic Valve Implantation (TAVI) for severe or inoperable aortic stenosis (AS) have concomitant mitral regurgitation (MR) . Prior work has suggested that mitral regurgitation is correlated with echocardiographic and clinical outcomes.

Hypothesis: Organic MR confers a higher risk of cardiac complications than functional MR.

Methods: High risk or inoperable patients who underwent TAVI for AS at Emory University or Hadassah University had echocardiograms at baseline and early follow up (within 30 days) and were followed for long-term clinical outcomes. MR was graded as functional or organic, and minimal (none-mild) or significant (mod-severe).

Results: 257 patients with MR (53% functional, 47% organic) underwent TAVR reducing mean aortic valve gradients by 36 mmHg. Patients with functional MR were more likely to be male but otherwise had similar baseline characteristics and early follow-up outcomes. Significant functional MR patients (n=53) had a greater improvement in MR and pulmonary artery systolic pressure (PASP) vs. significant organic MR patients (n=55) (38% vs. 28% achieving minimal MR, p<0.001; 5.9 mmHg vs 3.4 mmHg PASP, P=0.03). Organic MR was associated with a worse survival free of death/CHF than functional MR (mean follow up = 738 days; P=0.03, Figure 1). Multivariate analysis showed functional MR, an Edwards valve, and larger mean change in AV gradient were protective against death/CHF (HR=0.49, 0.16, 0.92 P=0.002, <0.001, 0.01 respectively).

Conclusions: TAVR patients with functional MR had greater improvements PASP and MR severity, as well as increased survival free of death/CHF compared to organic MR.

Figure 1: Survival free of death or CHF