The edition · Cardiology
The primary-prevention ICD benefit after myocardial infarction has faded to nothing in the modern era
Pooled data from 32,214 patients show the mortality reduction from a primary-prevention defibrillator shrinking across three decades and disappearing in 2015–2020. Separately, ablate-and-pace beat pulmonary vein isolation in over-75s with persistent atrial fibrillation, and four doses of dapagliflozin halved acute kidney injury after cardiac surgery.
The edition in brief
Three findings worth your attention today, and the first is uncomfortable. The PROFID pooled cohort followed 32,214 patients with an ejection fraction of 35% or less after myocardial infarction and asked whether the survival benefit of a primary-prevention ICD, established in trials from the early 2000s, still holds. It does not appear to. The hazard ratio was 0.54 in 1995–2004, 0.67 in 2005–2014, and 0.89 with a confidence interval crossing 1.0 in 2015–2020, with the interaction across periods highly significant. This is observational and propensity-weighted, not a trial, so it cannot tell you to stop implanting. It does tell you the effect size your guidelines rest on was measured in an era of different background therapy. The ABLATE versus PACE trial randomised 196 patients aged 75 and over with symptomatic persistent atrial fibrillation and preserved ejection fraction to pacemaker plus atrioventricular-node ablation or to pulmonary vein isolation. The composite primary endpoint occurred in 24% versus 46% at twelve months, a hazard ratio of 0.45. The two arms failed in different ways: the PVI group returned with atrial fibrillation and cardioversions, the pace-and-ablate group with heart failure admissions. And dapagliflozin, given as four doses around elective cardiac surgery, reduced acute kidney injury from 52% to 28% in 784 patients. The effect is large and the intervention is trivial, which is a combination worth reading twice. Also today: pulsed-field ablation matched cryoballoon overall but beat it in paroxysmal atrial fibrillation, and a 67,873-patient meta-analysis found no class-level heart failure signal for DPP-4 inhibitors, with saxagliptin still the exception.
The ICD mortality benefit after infarction has shrunk with every decade, and is now absent
The survival benefit of a primary-prevention ICD after infarction appears to have shrunk to nothing in patients enrolled since 2015, though this is observational data and not a reason to change indications today.
In over-75s with persistent atrial fibrillation, ablate-and-pace beat pulmonary vein isolation
For a symptomatic patient over 75 with persistent atrial fibrillation and a normal ejection fraction, pace-and-ablate more than halved a composite of arrhythmia and heart failure events compared with pulmonary vein isolation.
Four doses of dapagliflozin around cardiac surgery halved acute kidney injury
Dapagliflozin started the day before elective cardiac surgery and continued for four doses reduced KDIGO-defined acute kidney injury from 52% to 28%, though the endpoint is a sensitive one and harder outcomes were not assessed.
Pulsed-field ablation matched cryoballoon overall, and beat it in paroxysmal atrial fibrillation
Pulsed-field ablation is faster and much less likely to cause phrenic nerve palsy than cryoballoon, and reduces recurrence in paroxysmal atrial fibrillation specifically, but not across all comers.
No new regulatory action today, and the DPP-4 heart failure question stays where it was
Nothing new from the regulators today; the pooled randomised evidence continues to show no heart failure signal for DPP-4 inhibitors as a class, with saxagliptin the exception.
Ask how the strategy fails, not only whether it works
When a trial reports a composite endpoint, read the component breakdown before you quote the summary figure — two strategies can differ in how they fail rather than in how often.
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