Randomized Comparison of Percutaneous Repair and Surgery for Mitral Regurgitation

Getting approval for new therapeutic medical devices versus drugs: are the differences justified?

In the so-called evidence-based medicine (EBM) era, pre-market clinical trials showing equivalent or superior benefit from new drugs versus existing therapies are required by regulatory bodies, while the process for approval of medical devices is less stringent [1]. The expansion of device-based therapies for cardiovascular conditions makes cardiology the ideal setting for analysing the peculiarities of this process [2].

Lessons learned from cardiology: the process for approval of medical therapeutic devices must be redesignedhttp://ow.ly/bJPm3017ySH

[Interdisciplinary differential treatment of structural heart disease : When operation and when catheter-based intervention?]

The demographic changes in society lead to an increasing number of patients with aortic valve stenosis and mitral regurgitation. Simultaneously the higher age of patients is associated with an increase in multimorbidity with a high surgical risk so that they cannot be referred to surgery. Besides the current gold standard of surgery, minimally invasive therapeutic options are increasingly becoming established for these patients. For the differentiated indications and therapeutic success, a multidisciplinary heart team assumes an important role. The next generation of transcatheter aortic valve implantation (TAVI) systems will lead to improvement in the results, lower complication rates and mortality and as a result there is a general trend towards expanding the indications. New innovative minimally invasive mitral valve devices are still undergoing clinical trials and will define future therapy options.

Editor-in-Chief's Top Picks From 2015: Part Two

Each week, I record audio summaries for every article in JACC, as well as an issue summary. While this process has been time-consuming, I have become very familiar with every paper that we publish. Thus, I have personally selected the papers (both original investigations and review articles) from 13 distinct specialties for your review. In addition to my personal choices, I have included manuscripts that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. There are approximately 130 articles selected across this 2-part series, which represent less than 3% of the papers submitted to the Journal in 2015. In order to present the full breadth of this important research in a consumable fashion, we will present these manuscripts over the course of 2 issues in JACC. Part One includes the sections: Congenital Heart Disease, Coronary Disease & Interventions, CVD Prevention & Health Promotion, Cardiac Failure, Cardiomyopathies, Genetics, Omics, & Tissue Regeneration, and Hypertension. Part Two includes the sections: Imaging, Metabolic Disorders & Lipids, Rhythm Disorders, Statistics, Valvular Heart Disease, and Vascular Medicine (1-63).

Percutaneous mitral valve repair: The MitraClip device

Chronic mitral regurgitation (MR) is the most common cardiac valvular disease with more than 4 million people in the United States alone suffering from moderate or severe MR. Left untreated, chronic MR results in serious consequences. Surgical correction with mitral valve repair or replacement remains the mainstay of therapy for MR. Nevertheless, a large proportion of patients may not be offered treatment due to concerns over surgical risk. This unmet therapeutic need for a less invasive approach led to a marked explosion in the development of a variety of transcatheter approaches to treat mitral regurgitation in the past decade. The majority of these devices are based on principles learned from surgical mitral valve repair techniques. Inspired by the Alfieri surgical technique, the MitraClip edge-to-edge repair system is the most advanced technique with the highest safety and efficacy to date. In this review, we discuss the current status of the MitraClip repair system in the treatment of mitral regurgitation.

Early Hemodynamic Improvement after Percutaneous Mitral Valve Repair Evaluated by Noninvasive Pressure-Volume Analysis

BACKGROUND

Mitral regurgitation represents a volume load on the left ventricle leading to congestion and symptoms of heart failure. The aim of this study was to characterize early hemodynamic adaptions after percutaneous mitral valve (MV) repair.

METHODS

Forty-six consecutive patients with symptomatic high-grade MV insufficiency (mean age, 72 years; 54% men) were prospectively included in the study and examined before and after successful catheter-based clip implantation. Seventy percent of patients had secondary mitral regurgitation. Noninvasive pressure-volume loops were reconstructed from echocardiography with simultaneous blood pressure measurements.

RESULTS

MV repair reduced left ventricular end-diastolic volume index from 87 ± 41 to 80 ± 40 mL/m(2) (P < .0001). End-systolic volume index was 55 ± 37 mL/m(2) before versus 54 ± 37 mL/m(2) after repair (P = .52). Hence, total stroke volume decreased from 60 ± 23 to 49 ± 16 mL (P < .0001), as did total ejection fraction (from 41 ± 14% to 37 ± 13%, P = .002) and global longitudinal strain (from -11 ± 4.9% to -9.1 ± 4.4%, P = .0001). Forward stroke volume, forward ejection fraction, and forward cardiac output remained constant (43 ± 12 mL vs 42 ± 11 mL, 33 ± 17% vs 35 ± 18%, and 3.2 ± 0.9 L/min vs 3.4 ± 0.8 L/min, respectively). Parameters of left ventricular contractility (end-systolic elastance and peak power index) and measurements of afterload (arterial elastance, end-systolic wall stress, and total peripheral resistance) were similar before and after MV repair. Forward ejection fraction correlated more strongly with end-systolic elastance (r = 0.61, P < .0001) than did total ejection fraction (r = 0.35, P = .0007) or global longitudinal strain (r = -0.38, P = .0002). Total mechanical energy (pressure-volume area) decreased from 10,903 ± 4,410 to 9,124 ± 2,968 mm Hg × mL (P = .0007) because of reduced stroke work (5,546 ± 2,241 mm Hg × mL vs 4,414 ± 1,412 mm Hg × mL, P < .0001). At 3 months, symptom status had improved (76% of patients in New York Heart Association classes I and II), and 97% of patients had mitral regurgitation grade ≤2+.

CONCLUSIONS

Left ventricular contractility and forward cardiac output remained unchanged after percutaneous MV repair despite decreases in total ejection fraction and global longitudinal strain. The left ventricle was unloaded through reduced end-diastolic volume. Thus, MV repair is associated with an improved hemodynamic state in noninvasive pressure-volume analysis.