Evaluating Clinical Applicability

Percutaneous Ventricular Restoration with a Partitioning Device for Ischemic Heart Failure Treatment

PURPOSE OF THE REVIEW

Percutaneous ventricular restoration with a ventricular partitioning device (VPD) is a novel minimally invasive procedure designed to restore the left ventricular (LV) shape by isolating the infarcted and aneurysmal LV apex from remainder of the cavity in heart failure patients with severely reduced LV ejection fraction. In this review, we perform an in-depth analysis of the design and purpose of the VPD and review the available clinical data, with special attention to hemodynamics, outcomes, and complications.

RECENT FINDINGS

PARACHUTE trials have shown >90% procedural success rate of VPD implant. Heart failure patients had improvement in hemodynamics (reduction in LV volumes and increase in LV ejection fraction) and functional status (6-min walking distance and quality of life scores) after the VPD implant. Optimal implant position is necessary to obtain a good clinical outcome. Percutaneous VPD implantation has thus far been a safe intervention capable of improving surrogate markers of heart failure but there is still a need to develop more durable devices with a long-lasting hemodynamics effect.

Regional left ventricular function does not predict survival in ischaemic cardiomyopathy after cardiac surgery

OBJECTIVES

To define the prognostic contribution of global and regional left ventricular (LV) function measurements in patients with ischaemic cardiomyopathy randomised to coronary artery bypass graft surgery (CABG) with (n=501) or without (n=499) surgical ventricular reconstruction (SVR).

METHODS

Novel multivariable methods to analyse global and regional LV systolic function were used to better formulate prediction models for long-term mortality following CABG with or without SVR in the entire cohort of 1000 randomised SVR hypothesis patients. Key clinical variables were included in the analysis. Regional function was classified according to the discreteness of anteroapical hypokinesia and akinesia into those most likely to benefit from SVR, those least likely and those felt to have intermediate likelihood of benefit from SVR.

RESULTS

The most prognostic clinical variables identified in multivariable models include creatinine, LV end-systolic volume index (ESVI), age and NYHA (New York Heart Association) class. Addition of LV ejection fraction, LV end-diastolic volume index and regional function assessment did not contribute additional power to the model. Subgroup analysis based on regional function did not identify a cohort in which SVR improved mortality.

CONCLUSIONS

ESVI is the single parameter of LV function most predictive of mortality in patients with LV systolic dysfunction following CABG with or without SVR in multivariable models that include all key clinical and LV systolic function parameters. Assessment of regional cardiac function does not enhance prediction of mortality nor identify a subgroup for which SVR improves mortality. These results do not support elective addition of LV reconstruction surgery in patients undergoing CABG.

TRIAL REGISTRATION NUMBER

NCT00023595.

Devices in heart failure--the new revolution

Heart failure is a growing epidemic, with more patients living longer and suffering from this disease. There is a growing segment of patients who have persistent symptoms despite pharmacologic therapy. In an era when transplants are rare, the need for devices and interventions that can assist ventricular function is paramount. This review goes through the devices used in heart failure, including left ventricular reconstruction, aortic counterpulsation, short-term mechanical circulatory support, long-term mechanical circulatory support, and right heart interventions.

Assessing the available techniques for testing myocardial viability: what does the future hold?

Left ventricular dysfunction in the setting of severe coronary artery disease poses a major diagnostic and therapeutic dilemma. While this clinical scenario is generally associated with poor outcomes, some but not all patients benefit from coronary revascularization. For example, patients with severe, transmural myocardial infarctions may derive little or no functional benefit from revascularization, as the underlying myocardium is irreversibly scarred. Furthermore, these patients may be exposed to high procedural risks with a low likelihood of deriving any perceivable benefit. Conversely, hibernating myocardium reflects a substrate whereby the nonfunctioning myocytes are chronically ischemic but may be viable. Existing data are somewhat inconclusive with regard to the benefits of performing viability testing in patients with ischemic cardiomyopathy. While this testing may predict regional and global functional myocardial recovery, the ability of viability studies to predict survival and prognosis remains unproven in prospective studies to date. Yet, viability testing may still be a valuable tool to guide therapeutic options in selected patients. A variety of noninvasive viability tests are available and newer technologies, such as PET and cardiac MRI, are likely to advance the scientific field in years to come.

The PARACHUTE IV trial design and rationale: percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure and dilated left ventricles

BACKGROUND

Left ventricle (LV) remodeling after anterior wall myocardial infarction leads to increased LV volumes, myocardial stress, and, ultimately, heart failure (HF). Patients have high morbidity and mortality risk, and treatment remains limited. Percutaneous ventricular restoration (PVR) therapy using the Parachute device, a fluoropolymer membrane stretched over a nitinol conical frame, is a novel approach to partition off the damaged myocardium. In the European and United States PARACHUTE feasibility trials, the observed rates of death or rehospitalization for HF were <17% at 12 months. These data compare favorably with historical data and support the need of a randomized trial to determine the clinical efficacy of PVR on outcomes for patients with ischemic HF.

OBJECTIVE

To determine the safety and efficacy of PVR utilizing a LV partitioning device, Parachute, in a randomized clinical trial compared with optimal medical therapy.

METHODS

This US pivotal trial is approved by the Food and Drug Administration (ClinicalTrials.gov Identifier: NCT01286116) and will randomly assign (1:1) 478 patients with New York Heart Association class III-IV ischemic HF, akinetic or dyskinetic LV wall abnormality, and ejection fraction between 15% and 35% to optimal medical therapy (control) versus Parachute device implantation in approximately 65 hospitals. The primary endpoint is death or rehospitalization for worsening HF. Sample size calculation assumes constant hazards and follow-up ≥12 months using an event-driven trial design.

CONCLUSIONS

We reported the rational and design of the first multicenter randomized trial to test the efficacy of PVR using the Parachute device to treat patients with ischemic HF and dilated LV.