Cardiac Resynchronization Therapy for Heart Failure

number of randomized clinical trials have clearly established that cardiac resynchronization therapy (CRT) improves ventricular function and symptom status while reducing hospitalizations and mortality in heart failure patients with left ventricular ejection fraction (LVEF) 35% who have New York Heart Association class III or IV symptoms despite optimal medical management, are in sinus rhythm, and have evidence of ventricular electromechanical dyssynchrony.1 Because the outcomes for patients with heart failure remain poor despite maximal pharmacotherapy and because the magnitude of the benefits from CRT is similar to that reported for angiotensin-converting enzyme inhibitors and -blockers, the rapid increase in CRT device implants in patients with heart failure over the past few years is not surprising.2 Although ongoing trials continue to test the efficacy and safety of CRT in patient groups who were underrepresented or excluded from prior trials, the CRT evidence base is evolving and following the well-established pattern of investigation for technological advances in which health services researchers follow the clinical trialists into an area to evaluate the uptake, effectiveness, and safety of new technologies when deployed in routine clinical practice. As a first step in this process, the study by Piccini and colleagues3 in this week's Circulation examines who is, and who is not, receiving CRT in routine clinical practice. Article p 926 In their prospective cohort study of patients hospitalized for heart failure between 2005 and 2007 in 228 US hospitals participating in the American Heart Association's Get With the Guidelines-Heart Failure Program, Piccini et al3 had access to detailed clinical information that permitted them to explore the predictors of CRT use. It should be noted that these patients (median age, 73 years; median LVEF, 35%) were well cared for: 87% of those with left ventricular systolic dysfunction were prescribed an angiotensin- converting enzyme inhibitor or angiotensin receptor blocker and 89% were prescribed a -blocker, and 91% of smokers received smoking cessation counseling. Furthermore, patients receiving CRT in this cohort were more likely to receive evidence-based therapies such as -blockers, aldosterone antagonists, and lipid-lowering therapy than those who did not receive CRT. After excluding patients with new-onset heart failure and those without LVEF assessments, Piccini et al3 found that 12% of 33 898 heart failure patients were discharged with a CRT in situ and that patients were less likely to have a CRT device implanted if they were black (odds ratio (OR), 0.45; 95% CI, 0.36 to 0.57), were from the Northeast (OR, 0.40; 95% CI, 0.30 to 0.53, compared with the West), were older (OR, 0.56; 95% CI, 0.48 to 0.65, for patients 70 years of age), or had comorbidities such as chronic renal disease, diabetes, pulmonary disease, or cere- brovascular disease (OR, 0.33 to 0.73). It would not surprise any reader of health services literature to learn that CRT use varied widely between hospitals, across geographic regions, and between patient subgroups.4 Nor would readers be surprised by the finding that CRT recipients in clinical practice are older and have more comorbidities