Treatment of functional mitral regurgitation by percutaneous annuloplasty: results of the TITAN Trial

Abstract

Aims: Functional mitral regurgitation (FMR) contributes to morbidity and mortality in heart failure (HF) patients. The aim of this study was to determine whether percutaneous mitral annuloplasty could safely and effectively reduce FMR and yield durable long-term clinical benefit.

Methods and results: The impact of mitral annuloplasty (Carillon Mitral Contour System) was evaluated in HF patients with at least moderate FMR. Patients in whom the device was placed then acutely recaptured for clinical reasons served as a comparator group. Quantitative measures of FMR, left ventricular (LV) dimensions, New York Heart Association (NYHA) class, 6 min walk distance (6MWD), and quality of life were assessed in both groups up to 12 months. Safety and key functional data were assessed in the implanted cohort up to 24 months. Thirty-six patients received a permanent implant; 17 had the device recaptured. The 30-day major adverse event rate was 1.9%. In contrast to the comparison group, the implanted cohort demonstrated significant reductions in FMR as represented by regurgitant volume [baseline 34.5 ±11.5 mL to 17.4 ±12.4 mL at 12 months (P < 0.001)]. There was a corresponding reduction in LV diastolic volume [baseline 208.5 ±62.0 mL to 178.9 ±48.0 mL at 12 months (P =0.015)] and systolic volume [baseline 151.8 ±57.1 mL to 120.7 ±43.2 mL at 12 months (P =0.015)], compared with progressive LV dilation in the comparator. The 6MWD markedly improved for the implanted patients by 102.5 ±164 m at 12 months (P =0.014) and 131.9 ±80 m at 24 months (P < 0.001).

Conclusion: Percutaneous reduction of FMR using a coronary sinus approach is associated with reverse LV remodelling. Significant clinical improvements persisted up to 24 months.

Figure 1

Fluoroscopic image of an implanted Carillon device illustrates the coronary sinus position along the posterior mitral annulus. Tissue plication is maintained between the great cardiac vein anchor and the coronary sinus anchor.

Figure 2

Echocardiographic changes in functional mitral regurgitation severity between implanted (n =36) and non-implanted (n =17) patients as assessed by regurgitant volume (RV), effective regurgitant orifice area (EROA), vena contracta (VC), and mitral regurgitation jet area/left atrial area (MRJA/LAA). P-values were computed by comparing the difference between the two groups from baseline to 12 months. The number of patients at each time point is noted in parentheses in the tables corresponding to each plot.

Figure 3

Echocardiographic changes in left ventricular (LV) dimensions between implanted (n =36) and non-implanted (n =17) patients assessed during systole and diastole. P-values were computed by comparing the difference between the two groups from baseline to 12 months. The number of patients at each time point is noted in parentheses in the tables corresponding to each plot.

Figure 4

Comparison of clinical outcome measures between implanted (n =36) and non-implanted (n =17) patients assessed by 6 min walk distance (6MWD) and Kansas City Cardiomyopathy Questionnaire (KCCQ). P-values were computed by comparing the difference between the two groups from baseline to 12 months. The number of patients at each time point is noted in parentheses in the tables corresponding to each plot.