Effect of elevated pulmonary vascular resistance on outcomes after percutaneous mitral valvuloplasty

Very Long Term Follow-Up After Percutaneous Balloon Mitral Valvuloplasty

OBJECTIVES

The aim of this study was to assess very long term outcomes after successful percutaneous balloon mitral valvuloplasty (PBMV).

BACKGROUND

PBMV remains the preferred treatment for patients with severe symptomatic rheumatic mitral stenosis and suitable anatomy.

METHODS

All consecutive patients who underwent successful PBMV between 1987 and 2010 were included. The primary endpoint was the composite of all-cause mortality, need for mitral surgery, or repeat PBMV up to 23 years.

RESULTS

Among all 1,582 consecutive patients undergoing PBMV, acute success was achieved in 90.9% (n = 1,438). Independent predictors of acute success included left atrial size (odds ratio: 0.96; 95% confidence interval [CI]: 0.93 to 0.99; p = 0.045), Wilkins score ≤8 (odds ratio: 1.66; 95% CI: 0.48 to 0.93; p = 0.02) and age (odds ratio: 0.97; 95% CI: 0.96 to 0.99; p = 0.006). Very long term follow-up (median 8.3 years, mean 15.6 years) was obtained in 79.1% of successful cases. The incidence of the primary endpoint was 19.1% (95% CI: 17.0% to 21.1%). The rates of overall mortality, need for mitral valve surgery, or repeat PBMV were 0.6% (95% CI: 0.3% to 1.2%), 8.3% (95% CI: 7.0% to 9.9%), and 10.0% (95% CI: 8.5% to 11.7%), respectively. On multivariate analysis, New York Heart Association functional class III or IV (hazard ratio: 1.62; 95% CI: 1.26 to 2.09; p < 0.001), higher age (hazard ratio: 0.97; 95% CI: 0.96 to 0.98; p = 0.028), and mitral valve area ≤1.75 cm² after the procedure (hazard ratio: 1.67; 95% CI: 1.28 to 2.11; p = 0.028) were independent predictors of the primary endpoint.

CONCLUSIONS

In very long term follow-up, more than 75% of patients exhibited sustained results. Prediction of late favorable results is multifactorial and strongly determined by age, previous symptoms and post-procedural mitral valve area.

Epidemiology of Pulmonary Hypertension in Left Heart Disease

Pulmonary hypertension (PH) in the setting of left side heart disease is associated with adverse outcomes. The exact prevalence of PH in the different pathologies that affect the left ventricle, however, is difficult to access with the current literature. The lack of a standard definition of PH in older studies, the different modalities to assess pulmonary artery pressures and the varying disease severity, all account for the great variability in the reported prevalence of PH. PH can accompany heart failure (HF) with reduced (HFrEF) or preserved ejection fraction (HFpEF) as well as mitral and aortic valve disease; in any of these instances it is important to recognize whether the elevation of pulmonary pressures is driven by elevated left ventricular pressures only (isolated post-capillary PH) or if there is an accompanying remodeling component in the pulmonary arterioles (combined post-capillary and pre-capillary PH). The objective of this review is to describe the definitions, prevalence and the risk factors associated with the development of PH in the setting of HFrEF, HFpEF and valvular heart disease.

Predictors of Very Late Events After Percutaneous Mitral Valvuloplasty in Patients With Mitral Stenosis

Data on long-term outcomes of percutaneous mitral valvuloplasty (PMV) are still scarce. In addition, the persistence of pulmonary hypertension (PH) after PMV is a complication for which mechanisms and prognostic implications are unclear. Our aims were (1) to report the long-term outcomes of patients with rheumatic mitral stenosis treated with PMV; (2) to determine the risk factors for long-term poor outcomes; and (3) to analyze the prevalence and predictors of persistent PH. We prospectively enrolled 532 patients who underwent PMV from 1987 to 2011 at 2 hospitals. The following end points were assessed after PMV: all-cause mortality, mitral reintervention, a composite end point of all-cause mortality and mitral reintervention, and PH persistence. Survival status was available for 97% patients; the median follow-up was 10 years (interquartile range 4 to 18 years). Procedural success was achieved in 85% patients. During the follow-up, 21% patients died and 27% required mitral reintervention. Before PMV, 74% patients had PH that persisted after PMV in 45% of patients (p <0.001). Unfavorable valve anatomy (Wilkins score >8) and post-PMV mean pulmonary arterial pressure (PAP) were independent predictors of all-cause mortality, mitral reintervention, and the composite end point. Post-PMV mean PAP was significantly correlated with a mitral valve area (MVA) <2.5 cm(2) (p <0.001); in addition, on the echocardiographic follow-up, MVA was an independent predictor of systolic PAP (p <0.001). In conclusion, PMV represents an advantageous therapeutic option for patients with mitral stenosis in terms of long-term outcomes. Unfavorable valve anatomy and persistent PH were the most important predictors of long-term outcomes. The persistence of PH is associated with the MVA obtained after PMV.

Predictors of persistent pulmonary hypertension after mitral valve replacement

Persistent pulmonary hypertension (P-PH) after mitral valve replacement (MVR) leads to an increased risk of morbidity and mortality. We sought to determine which factors were involved in its occurrence. Patients undergoing MVR for a 3-year period were collected in a retrospective way. We excluded those with an available follow-up shorter than 3 months. Sample size was 111 patients. PH was diagnosed if systolic pulmonary artery pressure (sPAP) estimated by Doppler echocardiography was >40 mmHg. Clinical, echocardiographic, and surgical factors were analyzed. P-PH was present in 42.3 % of patients after 12.6 months of mean follow-up. P-PH was more frequently observed in elderly and female patients, in those with severe degrees of PH before surgery, and significant tricuspid regurgitation (TR). On multivariable analysis, significant TR (OR 1.739; p = 0.01) and more severe degrees of PH before surgery (OR 1.761; p = 0.03) were significantly associated with the presence of P-PH after MVR. Surgical factors related to P-PH were prosthesis size and tricuspid annuloplasty: no need for the performing of tricuspid annuloplasty (OR 0.345; p = 0.025) and the implantation of a smaller prosthesis (OR 0.656; p = 0.004) were related to higher rates of P-PH after MVR. MVR was associated with high prevalence of P-PH after mid-term follow-up. Both PH and significant TR before surgery were associated with P-PH. Our data point out that MVR should be planned before the development of PH and greater TR. Smaller prosthetic size is also a risk factor for P-PH and bigger prostheses are desirable when possible.