Budapest Upgrade CRT Study (Version 009-4.1)

The aim of this study is to investigate the effect of upgrade to a CRT-D device on clinical and echocardiographic response at 12-month in patients with left ventricular dysfunction (LVEF ≤35%), symptomatic heart failure (NYHA II, III, IV-a), and intermittent or permanent right ventricular pacing with paced QRS complex ≥ 150 ms compared to continued therapy with a single or dual chamber pacemaker (PM) or ICD.

Prospective, post-market, international multicenter randomized controlled trial.

Inclusion criteria

• Male or female patients over the age of 18 (expected survival time: over 1 year)
• Patients with ischemic or non-ischemic cardiomyopathy;
• Those implanted with a single or dual chamber ICD or implanted with a single or dual chamber pacemaker at least 6 months before inclusion;
• Elective generator replacement or upgrade from pacemaker-only to ICD therapy may be indicated at the time of enrollment, but are not required;
• Right ventricular pacing 20-100% in at least the last 90 days before enrollment (with an optimal AV interval based on the physician's discretion to avoid unnecessary right ventricular stimulation);
• Symptomatic heart failure for at least 3 months before inclusion;
• NYHA functional class II or III, or IV a;
• Left ventricular ejection fraction measured by echocardiography ≤ 35%;
• Paced QRS complex ≥ 150 ms;
• Optimal heart failure medical therapy;
• Informed consent obtained.

Exclusion criteria

• Intrinsic QRS with LBBB morphology (measured at VVI 40 bpm setting as per protocol);
• CABG or PCI in the past 3 months;
• Acute myocardial infarction in the past 3 months;
• Unstable angina;
• Planned coronary revascularization (PCI or CABG);
• Planned cardiac transplantation;
• Acute myocarditis;
• Infiltrative myocardial disease;
• Hypertrophic cardiomyopathy;
• Severe primary mitral and aortic valve stenosis or regurgitation;
• Women who are pregnant or plan to become pregnant or breastfeeding;
• Subjects who are unable or unwilling to cooperate with the study protocol;
• Tricuspid valve prosthesis;
• Any serious disease likely to interfere with the conduct of the study;
• Participation in other clinical trial;
• Patients geographically not stable or unavailable for follow-up;
• Chronic, severe renal dysfunction (creatinine value > 200 μmol/l);
• Severe RV dilatation (RV basal diameter >50mm);
• Severe tricuspid insufficiency.