Practice Update: Cardiology

ESC 2016 19

ICD does not improve overall survival in nonischaemic heart failure

L ars Kober, MD, of Copenhagen University Hospital, Denmark, explained that the results suggest a caveat to both European and American Heart Association guidelines that recommend implantable cardioverter-defibrillators for all heart failure. DANISH stands for DANish randomised, controlled, multicentre study to assess the efficacy of Implantable Cardioverter Defibrillator (ICD) in patients with nonischaemic Systolic Heart failure on mortality. Dr Kober said, “Prophylactic cardioverter- defibrillator implantation is a class 1 recommendation in patients with heart failure and reduced left ventricular systolic function in both European and American guidelines. The evidence is much weaker, however, for patients with non-ischaemic aetiology. Limited data supports the devices in this population. The DANISH trial filled that gap by suggesting the cardioverter-defibrillators should not be routinely implanted in all patients with systolic heart failure.” A total of 1116 stable patients with chronic, nonischaemic, symptomatic heart failure were randomised to usual care including guideline- recommended medications such as including

Placement of an implantable cardioverter-defibrillator in patients with nonischaemic systolic heart failure did not improve overall survival compared with usual clinical care. Risk of sudden cardiac death, however, was halved, reports the DANISH trial.

Patients at high risk of non-sudden death ... may not benefit, and age should be an important factor in the decision to implant the device, along with comorbidities.

the control group (hazard ratio 0.50; 95% CI 0.31 to 0.82; P = 0.01). Results were independent of whether or not a patient received a cardiac resynchronisation device, but an important interaction with age was observed. Dr Kober said, “Patients younger than 68 years of age had a significant reduction in all-cause mortality if they received an ICD (hazard ratio 0.64; 95% CI 0.45 to 0.90, P = 0.01), suggesting that younger patients may experience a survival benefit with implantation of the device.” Fifty-eight percent of controls had received a biventricular pacemaker and device-related infections occurred in both groups. Patients not receiving cardiac resynchronisation therapy in the ICD group, however, were at excess risk of device infection (5.1% vs 0.8% in controls; HR 6.35; 95% CI 1.38 to 58.87; P = 0.006). Inappropriate shocks, another risk associated with ICD, occurred in 5.9% of the ICD group. American Heart Association guidelines include ICD implantation as a class 1A recommendation for primary prevention of all- cause mortality in patients with symptomatic systolic heart failure, with no differentiation between patients with ischaemic and nonischaemic aetiology. European guidelines carry a class IB recommendation specifically for patients with nonischaemic heart failure. Dr Kober concluded, “Guidelines are based on multiple studies. Implantable cardioverter- defibrillator treatment should still carry a class 1A recommendation for prevention of sudden cardiac death in nonischaemic heart failure also. Patients at high risk of non- sudden death, however, may not benefit, and age should be an important factor in the decision to implant the device, along with comorbidities.”

beta blockers, renin- angiotensin inhibitors, and mineralocorticoid-receptor antagonists (n = 560); or an ICD (n = 556). An equal proportion of patients (58%) in both groups also needed cardiac resynchronisation therapy, which was delivered via biventricular pacemaker in the control arm, and a device combining cardiac resynchronisation therapy and ICD in the ICD arm. After a median of 67.6 months, the primary outcome of death from all causes occurred in 21.6% of ICD patients and 23.4% of controls, a nonsignificant difference. Sudden death, a secondary outcome, occurred in 4.3% of ICD patients and was almost doubled (8.2%) in

DECEMBER 2016