Cardiac contractility modulation: a novel approach for the treatment of heart failure

Heart failure is a major health problem worldwide and, despite effective therapies, is expected to grow by almost 50 % over the next 15 years. Five-year mortality remains high at 50 % over 5 years. Because of the economic burden and large impact on quality of life, substantial effort has focused on treatments with multiple medical (beta-blockers, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ARB), aldosterone antagonists, and combination of ARB/neprilysin blockers, ivabradine) and device therapies (ICD, CRT) which have been implemented to reduce disease burden and mortality. However, in the past decade only two new medical therapies and no devices have been approved by the US FDA for the treatment of heart failure. This review highlights the preclinical and clinical literature, and the implantation procedure, related to a relatively new therapeutic device for heart failure; cardiac contractility modulation (CCM). CCM delivers a biphasic high-voltage bipolar signal to the RV septum during the absolute refractory period, eliciting an acute increase in global contractility, and chronically producing a sustained improvement in quality of life, exercise tolerance, and heart failure symptoms. The technology is used commercially in Europe with nearly 3000 patients implanted worldwide. Indications include patients with reduced EF and normal or slightly prolonged QRS duration, thus filling an important therapeutic gap among the 2/3 of patients with heart failure who do not meet criteria for CRT. The mechanism by which CCM provides benefit can be seen at the cellular level where improved calcium handling (phosphorylation of phospholamban, upregulation of SERCA-2A), reversal of the fetal myocyte gene program associated with heart failure, and reverse remodeling are observed. Recent retrospective studies indicate a long-term mortality benefit. A pivotal randomized controlled study is currently being completed in the USA. CCM appears to be an effective, safe technology for the treatment of heart failure with reduced ejection fraction.

Economic assessment of cardiac resynchronization therapy

INTRODUCTION AND OBJECTIVES

Cardiac resynchronization devices have been shown to be effective in treating heart failure. They reduce overall mortality, heart failure mortality and hospitalizations due to heart failure. The aim of this study was to compare the cost-effectiveness of cardiac resynchronization therapy (CRT) with that of optimal drug therapy (ODT) by carrying out an economic assessment in the Spanish healthcare setting.

METHODS

An existing model was adapted for use in the Spanish healthcare setting. The effectiveness of cardiac resynchronization therapy was determined from published systematic reviews. The costs of the various interventions were determined using a range of Spanish data sources. The model adopted the perspective of the public health system and the time horizon considered was the remainder of the patient's life. The outcome variables were life-years gained and quality-adjusted life-years (QALYs) gained.

RESULTS

Overall, ODT, CRT and CRT with a defibrillator resulted in gains of 2.11, 2.8 and 3.19 QALYs, respectively, at a cost of €11,722, €31,629 and €52,592, respectively. Consequently, each QALY gained with CRT relative to ODT involved the consumption of €28,612 of additional resources. Similarly, the use of CRT with a defibrillator cost an additional €53,547 per QALY relative to CRT without a defibrillator.

CONCLUSIONS

The use of CRT without a defibrillator could be a cost-effective alternative to ODT for treating heart failure in a carefully selected group of patients. The study results were sensitive to uncertainties in many of the variables used in the model.