Current practice of cardiac resynchronization therapy (CRT) in the real world: insights from the European CRT survey

Abstract

Large randomized controlled trials have demonstrated that cardiac resynchronization therapy (CRT) improves morbidity and mortality in patients with moderate to severe heart failure [New York Heart Association (NYHA) functional class III–IV], reduced left ventricular ejection fraction (LVEF ≤35%), and a broad QRS complex >120 ms on optimal medical therapy.1–3 As a result, the impressive survival benefit as well as the improvement in heart failure symptoms and quality of life observed in these trials have spurred interest in extending resynchronization therapy to a larger number of heart failure patients. Indeed, several lines of evidence indicate that currently employed guidelines (mainly based on the selection criteria used in the aforementioned pivotal trials) may not be perfect at identifying patients most likely to benefit from CRT, with a significant proportion of patients being ‘non-responders’ based on clinical outcomes or echocardiographic remodelling.4 Conversely, results from various small studies imply that certain patient populations may benefit from CRT despite the fact that they do not fulfil the criteria of current CRT guidelines.5–7 In the absence of randomized trials, data from large-scale ‘real world’ surveys provide a unique opportunity to study both the current practice regarding the employment of a novel type of therapy as well as its efficacy and safety, including ‘off-label’ indications. The European CRT Survey, a joint initiative by the Heart Failure Association (HFA) and the European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC), reports on the current European practice in the use of CRT.8 In order to provide this information, 2438 patients from 141 centres in 13 European countries who underwent successful implantation of a CRT device were followed from November 2008 until June 2009. In addition to providing a detailed description of …