Impact of Net Atrioventricular Compliance on Clinical Outcome in Mitral Stenosis

Abstract

Background Net atrioventricular compliance (Cn) has been reported to be an important determinant of pulmonary hypertension in mitral stenosis (MS). We hypothesized that, as Cn reflects hemodynamic consequences of MS, it may be useful in assessing prognosis. To date, limited data with an assumed Cn cutoff have indicated the need for larger prospective studies. This prospective study was designed to determine the impact of Cn on clinical outcome and its contribution to pulmonary pressure in MS. In addition, we aimed to identify a cutoff value of Cn for outcome prediction in this setting. Methods and Results A total of 128 patients with rheumatic MS without other significant valve disease were prospectively enrolled. Comprehensive echocardiography was performed and Doppler-derived Cn estimated using a previously validated equation. The endpoint was either mitral valve intervention or death. Cn was an important predictor of pulmonary pressure, regardless of classic measures of MS severity. During a median follow-up of 22 months, the endpoint was reached in 45 patients (35%). Baseline Cn predicted outcome, adding prognostic information beyond that provided by mitral valve area and functional status. Cn ≤ 4 mL/mmHg best predicted unfavorable outcome in derivation and validation sets. A subgroup analysis including only initially asymptomatic patients with moderate to severe MS without initial indication for intervention (40.6 % of total) demonstrated that baseline Cn predicted subsequent adverse outcome even after adjusting for classic measures of hemodynamic MS severity (hazard ratio [HR] 0.33, 95% confidence interval [CI] 0.14–0.79, p = 0.013). Conclusions Cn contributes to pulmonary hypertension beyond of stenosis severity itself. In a wide spectrum of MS severity, Cn is a powerful predictor of adverse outcome, adding prognostic value to clinical data and mitral valve area. Importantly, baseline Cn predicts a progressive course with subsequent need for intervention in initially asymptomatic patients. Cn assessment therefore has potential value for clinical risk stratification and monitoring in MS patients.

Net atrioventricular compliance is an independent predictor of cardiovascular death in mitral stenosis

“…A previous study13 with 26 patients evaluated the relation between C n and clinical events and found that low left atrial C n predicted the need for MV intervention. Subsequently, we demonstrated that C n was an important predictor of MV intervention,18 adding incremental prognostic value to clinical data and MV area. More recently, Mahfouz et al 19 showed that C n was significantly low in MS patients who had unfavourable outcome after successful PMV, but long-term mortality was not addressed in either of the prior studies.…”

“…However, limited data are available regarding the prognostic value of C n 13 18 19. We have previously shown that baseline C n is a powerful predictor of the need for MV intervention,18 but with few events, which limited analysis of the role of C n in predicting death and indicated the need for further studies.…”

Correlation of Net Atrioventricular Compliance with the Outcome of Successful Percutaneous Transvenous Mitral Valve Commissurotomy

“…17,18 Several factors may contribute to clinical presentation and outcome in MS. Leftheart compliance plays a crucial role in the occurrence of pulmonary hypertension and symptoms. 19 Li et al 20 Nunes et al 23 showed that net atrioventricular compliance,Cn <4 mL/mm Hg best predicted unfavorable outcome in patients with mitral stenosis and Cn was found as a powerful predictor of adverse outcome, adding prognostic information beyond that provided by clinical evaluation and MV area.…”

Impact of left atrial compliance improvement on functional status after percutaneous mitral valvuloplasty

“…Previous studies addressing the impact of atrial compliance on pulmonary artery pressure have used net atrioventricular compliance ( C n ), derived by Doppler echocardiography, which is comparable to invasively measured C av . We have previously demonstrated reasonable correlation ( r = 0.60) between C av and Doppler‐derived C n . As low atrial compliance is the main determinant of pathologic physiology in MS, C n is used as a surrogate for C a …”

“…Left atrial (LA) compliance ( C a ) modulates the overall hemodynamic burden of MS, contributing to deterioration of functional capacity, pulmonary hypertension, and death . In this context, changes in C a after PMV may have the potential role in predicting clinical outcomes.…”