Heart failure patients at risk of arrhythmias should not have to wait until after stent insertion before they are fitted with an implantable cardioverter defibrillator device (ICD), according to researchers, who identified a "clear window of missed opportunity" to reduce the risk of dying from abnormal heart rhythm.
Ventricular arrhythmia is a prominent cause of mortality in patients with ischaemic left ventricular dysfunction, and the rate of death or aborted sudden death remains high, despite the use of guideline-directed medical therapy, alerted the authors of a study, published in the journal Circulation.
Revascularisation with coronary artery bypass graft or percutaneous coronary intervention (PCI) was often recommended before cardiac defibrillator implantation because it was "assumed" that this might reduce the incidence of fatal and potentially fatal ventricular arrhythmias. However, the authors cautioned that to date, this premise had not been evaluated in a randomised trial.
No Need to Defer Implantation
For the prospective, randomised, multi-centre open-label trial (REVIVED-BCIS2) patients with ischaemic left ventricular systolic dysfunction were randomised to receive either PCI plus optimal medical and device therapy (OMT) or OMT alone.
Participants were recruited from 40 hospitals in the United Kingdom, and between August 2013, and March 2020, 700 participants were enrolled. Of those, 347 were assigned to the PCI group and 353 to the OMT group. The mean age of participants was 69 years, 88% were male, 56% had hypertension, 41% had diabetes, and 53% had a clinical history of myocardial infarction. The median left ventricular ejection fraction was 28%.
Among the patients assigned to the PCI group, 96.3% underwent PCI at a median of 35 days after randomisation, and 53.1% had an implantable defibrillator inserted before randomisation or during follow-up of up to 8 years.
The research team, led by consultant cardiologist Divaka Perera, professor of interventional cardiology at King's College London (KCL), found that all-cause death or aborted sudden death occurred in 41.6% of PCI group patients, and in 40.2% of OMT patients. There were 110 deaths (31.8%) in the PCI group and 115 (32.6%) in the OMT group. Aborted sudden death occurred in 44 patients (12.7%) in the PCI group and 47 patients (13.3%) in the OMT group.
In the analysis of the REVIVED-BCIS2 trial, a strategy of PCI in addition to OMT was not associated with a reduction in all-cause mortality or aborted sudden death in patients with ischaemic left ventricular dysfunction, compared with a strategy of OMT alone, highlighted the authors.
"Patients with stable ischaemic cardiomyopathy should not undergo PCI solely to reduce the burden of arrhythmias," they stressed, and added that for patients who were eligible for an ICD, "implantation does not need to be deferred until revascularisation has been performed".
Wait And See Approach Not Always Best
In addition, the findings "challenge the widespread practice" of undertaking a coronary artery bypass graft (CABG) or PCI in most patients who are candidates for ICD implantation to reduce the arrhythmic risk, the authors pointed out.
"In stable patients who are treated with guideline-directed medical therapy and meet criteria for implantable cardioverter defibrillator implantation, there is no evidence to support delaying implantation merely to assess the effect of percutaneous coronary intervention because the latter was not found to improve left ventricular function," explained the authors.
Patients with ischaemic left ventricular dysfunction should not undergo percutaneous coronary intervention with the sole aim of preventing the occurrence of ventricular arrhythmias, they commented.
Dr Holly Morgan, a British Heart Foundation clinical research fellow at KCL, said, "Our findings have revealed that many patients with high risk of heart failure could benefit from receiving an ICD straight away, rather than facing a 90-day wait." She said that in demonstrating how coronary stents had "limited benefit" for this group of patients, a "clear window of missed opportunity" to reduce chances of dying from an abnormal heart rhythm had been exposed.
The authors emphasised that the results provided new evidence which could "influence" heart failure guidelines in the UK, Europe, and internationally.
Dr Sonya Babu-Narayan, associate medical director at the BHF, which helped fund the investigation, said that the findings could lead to re-evaluation of how best to treat people living with severe heart failure due to coronary heart disease. The findings suggested that the current "wait and see" approach to find out whether a patient's heart function improved with medication and stents "isn't always best", she underlined, and warned that "an unnecessary wait could even be the difference between life and death".