Dataset Information

Percutaneous Mitral Valve Repair in Mitral Regurgitation Reduces Cell-Free Hemoglobin and Improves Endothelial Function.

ABSTRACT:

Background and objective

Endothelial dysfunction is predictive for cardiovascular events and may be caused by decreased bioavailability of nitric oxide (NO). NO is scavenged by cell-free hemoglobin with reduction of bioavailable NO up to 70% subsequently deteriorating vascular function. While patients with mitral regurgitation (MR) suffer from an impaired prognosis, mechanisms relating to coexistent vascular dysfunctions have not been described yet. Therapy of MR using a percutaneous mitral valve repair (PMVR) approach has been shown to lead to significant clinical benefits. We here sought to investigate the role of endothelial function in MR and the potential impact of PMVR.

Methods and results

Twenty-seven patients with moderate-to-severe MR treated with the MitraClip® device were enrolled in an open-label single-center observational study. Patients underwent clinical assessment, conventional echocardiography, and determination of endothelial function by measuring flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound at baseline and at 3-month follow-up. Patients with MR demonstrated decompartmentalized hemoglobin and reduced endothelial function (cell-free plasma hemoglobin in heme 28.9±3.8 ?M, FMD 3.9±0.9%). Three months post-procedure, PMVR improved ejection fraction (from 41±3% to 46±3%, p = 0.03) and NYHA functional class (from 3.0±0.1 to 1.9±1.7, p<0.001). PMVR was associated with a decrease in cell free plasma hemoglobin (22.3±2.4 ?M, p = 0.02) and improved endothelial functions (FMD 4.8±1.0%, p<0.0001).

Conclusion

We demonstrate here that plasma from patients with MR contains significant amounts of cell-free hemoglobin, which is accompanied by endothelial dysfunction. PMVR therapy is associated with an improved hemoglobin decompartmentalization and vascular function.

SUBMITTER: Rammos C

PROVIDER: S-EPMC4795750 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Project description:We aimed to identify predictors of mitral regurgitation recurrence (MR) after percutaneous mitral valve repair (PMVR) in patients with functional mitral regurgitation (FMR). Patients with FMR were enrolled who underwent PMVR using the MitraClip® device. Procedural success was defined as reduction of MR of at least one grade to MR grade ≤ 2 + assessed at discharge. Recurrence of MR was defined as MR grade 3 + or worse at one year after initially successful PMVR. A total of 306 patients with FMR underwent PMVR procedure. In 279 out of 306 patients (91.2%), PMVR was successfully performed with MR grade ≤ 2 + at discharge. In 11.4% of these patients, MR recurrence of initial successful PMVR after 1 year was observed. Recurrence of MR was associated with a higher rate of heart failure rehospitalization during the 12 months follow-up (52.0% vs. 30.3%; p = 0.029), and less improvement in New York Heart Association (NYHA) functional class [68% vs. 19% of the patients presenting with NYHA functional class III or IV one year after PMVR when compared to patients without recurrence (p = 0.001)]. Patients with MR recurrence were characterized by a higher left ventricular sphericity index {0.69 [Interquartile range (IQR) 0.64, 0.74] vs. 0.65 (IQR 0.58, 0.70), p = 0.003}, a larger left atrium volume [118 (IQR 96, 143) ml vs. 102 (IQR 84, 123) ml, p = 0.019], a larger tenting height 10 (IQR 9, 13) mm vs. 8 (IQR 7, 11) mm (p = 0.047), and a larger mitral valve annulus [41 (IQR 38, 43) mm vs. 39 (IQR 36, 40) mm, p = 0.015] when compared to patients with durable optimal long-term results. In a multivariate regression model, the left ventricular sphericity index [Odds Ratio (OR) 1.120, 95% Confidence Interval (CI) 1.039-1.413, p = 0.003)], tenting height (OR 1.207, 95% CI 1.031-1.413, p = 0.019), and left atrium enlargement (OR 1.018, 95% CI 1.000-1.038, p = 0.047) were predictors for MR recurrence after 1 year. In patients with FMR, baseline parameters of advanced heart failure such as spherical ventricle, tenting height and a large left atrium might indicate risk of recurrent MR one year after PMVR.

Project description:AimsTherapeutic options for patients with heart failure with preserved ejection fraction (HFpEF) are sparse. Mitral regurgitation (MR) is a common feature of HFpEF and worsens heart failure symptoms and prognosis. Our study examines the outcome of patients with preserved left ventricular ejection fraction (LVEF) and elevated left atrial (LAP) or left ventricular filling pressures (LVEDP), indicative of HFpEF, after undergoing percutaneous edge-to-edge mitral valve repair (pMVR) for moderate-severe MR.Methods and resultsTwo hundred eleven patients with preserved LVEF (>50%), who underwent pMVR, were dichotomized by LAP (< / ≥15 mmHg) and LVEDP (< / ≥16 mmHg). Forty-nine per cent of patients showed elevated LAP, and LVEDP was elevated in 55%, both indicating HFpEF. Patients with elevated filling pressures featured typical clinical characteristics of HFpEF, higher N-terminal pro-brain natriuretic peptide levels (5544.9 pg/mL in high LAP group vs. 3071.7 pg/mL in normal LAP group, P = 0.06; 5061.0 pg/mL in high LVEDP group vs. 3230.3 pg/mL in normal LVEDP group, P = 0.08), and higher prevalence of pulmonary hypertension (mean pulmonary artery pressure 36.4 mmHg in high LAP group vs. 26.3 mmHg in normal LAP group, P < 0.001; 35.2 mmHg in high LVEDP group vs. 29.7 mmHg in normal LVEDP group, P = 0.004) and atrial fibrillation (78.8% in normal LAP group vs. 61.0% in high LAP group, P = 0.04; 75.3% in high LVEDP group vs. 67.5% in normal LVEDP group, P = 0.25). Pre-treatment MR grade and New York Heart Association (NYHA) class were similar in both normal filling pressure and HFpEF groups. pMVR in HFpEF patients achieved effective heart failure symptom relief comparable with patients with normal filling pressures: significant decrease of MR grade and NYHA class, as well as significant reduction of heart failure hospitalizations 12 months after compared with 12 months before MitraClip.ConclusionPercutaneous edge-to-edge mitral valve repair for moderate-severe MR is an effective treatment option for symptom relief in HFpEF patients.