Global regurgitant volume: approaching the critical mass in valvular-driven heart failure

AIMS

Recent progress in the diagnosis of functional valve regurgitation forms a coherent perception of severity thresholds by quantitative assessment. However, thresholds focused on either valve in isolation-not accounting for the global haemodynamic burden arising from concomitant functional regurgitation of the mitral and tricuspid valves. We sought to determine whether the global regurgitant volume is associated with adverse cardiac remodelling and mortality.

METHODS AND RESULTS

This long-term observational study included 414 patients on guideline-directed medical therapy. Baseline global regurgitant load defined as the sum of mitral and tricuspid regurgitant volume was assessed by the proximal flow convergence method. All-cause mortality during 5 years follow-up served as the primary endpoint. The median global regurgitant load was 30 mL (interquartile range 15-49) with 67% accounting for mitral and 33% accounting for tricuspid regurgitant volume. The global regurgitant load had significant impact on outcome with a crude hazard ratio of 1.46 (1.28-1.66; P < 0.001) for a 1-SD increase in global regurgitant volume, results that remained virtually unchanged after bootstrap or clinical confounder-based adjustment (P < 0.001 for adjusted models). Spline curve analysis showed a linearly increasing risk with a threshold of 50 mL and sustained increasing risk thereafter.

CONCLUSIONS

The present study demonstrates the detrimental effect of the global regurgitant load in patients with heart failure with reduced ejection fraction. The threshold where heart failure is driven by the valve lesions is a global regurgitant volume of 50 mL with continuously increasing risk beyond that threshold. Future studies need to address whether an attempt to reduce the global regurgitant volume can improve outcome.

Natural history of bivalvular functional regurgitation

AIMS

Bivalvular functional regurgitation (BVFR) defined as concomitant mitral and tricuspid insufficiency has not been described or systematically assessed before. Therefore, this study sought to define incidence, impact and natural history of BVFR in heart failure with reduced ejection fraction (HFrEF) to provide the foundation for risk assessment and directions for potential treatment strategies.

METHODS AND RESULTS

We enrolled 1021 consecutive patients with HFrEF under guideline-directed medical therapy and performed comprehensive echocardiographic and neurohumoral profiling. All-cause mortality during a 5 years of follow-up served as the primary endpoint. Thirty percent of patients suffered from moderate or severe BVFR. Long-term mortality increased with the presence and severity of functional regurgitation (FR) with severe BVFR representing the highest risk-subset (P < 0.001). Severe BVFR patients were more symptomatic and displayed an adverse remodelling and neurohumoral activation pattern (all P < 0.05). Severe BVFR was associated with excess mortality independently of clinical [adjusted hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.39-1.84; P < 0.001] and echocardiographic (adjusted HR 1.31, 95% CI 1.11-1.54; P = 0.001) confounders, guideline-directed medical therapy (adjusted HR 1.55, 95% CI 1.35-1.79; P < 0.001) and neurohumoral activation (adjusted HR 1.31, 95% CI 1.07-1.59; P = 0.009). Moderate BVFR (n = 99) comprised equal baseline characteristics and similar risk as isolated severe FR (HR 0.95, 95% CI 0.69-1.30; P = 0.73).

CONCLUSION

This long-term outcome study shows the multi-faceted nature of FR and defines BVFR as an important clinical entity associated with impaired functional class, adverse cardiac remodelling, and excess risk of mortality. Moderate BVFR conveys similar risk as isolated severe FR reflecting the deleterious impact of the global regurgitant load on the failing heart and the need of an integrated understanding for risk-assessment.