Does cardiac rehabilitation after a heart attack work?

Exercise-based cardiac rehabilitation after a heart attack or a stent lowers the chance of another heart attack and of being admitted to hospital, but the best pooled evidence finds little to no effect on dying within the first year [s1]. It is a worthwhile programme with a more specific benefit than the common shorthand that it "saves lives" implies [s1].

Cardiac rehabilitation is a supervised course of exercise training, usually combined with education and psychological support, offered to people who have had a myocardial infarction, a coronary artery bypass graft or a percutaneous coronary intervention (a stent), or who have angina or coronary artery disease [s1]. The idea is old and intuitive: recondition the heart and the person after a cardiac event, and both do better. The harder question is how much of that intuition survives contact with the randomised evidence, now that nearly everyone leaving hospital after a heart attack also goes home on statins, antiplatelet drugs and blood-pressure treatment.

What the pooled trials show

The most complete answer comes from a 2021 Cochrane review that pooled 85 randomised trials enrolling 23,430 people with coronary heart disease, of which 22 trials with 7,795 participants were new to that update [s1]. Participants were mostly people recovering from a heart attack or a revascularisation procedure, with a mean age ranging from 47 to 77 across the trials [s1]. Two limits of the evidence base are worth stating up front: women made up fewer than 15% of participants overall, and the median longest follow-up was only 12 months [s1].

Within that first 6-to-12-month window, the pattern is not uniform across outcomes. Compared with no exercise, rehabilitation produced a large reduction in further heart attacks — a risk ratio of 0.72 (95% confidence interval 0.55 to 0.93), rated high-certainty evidence, with 75 people needing to attend for one to avoid a heart attack [s1]. It produced a comparably large reduction in all-cause hospitalisation, a risk ratio of 0.58 (95% confidence interval 0.43 to 0.77), with just 12 people needing to attend to prevent one admission [s1].

The mortality picture is where the story tightens. Rehabilitation likely produced only a slight reduction in all-cause death, a risk ratio of 0.87 whose confidence interval (0.73 to 1.04) crosses the line of no effect [s1]. For cardiovascular death specifically, the review concluded it makes "little to no difference," with a risk ratio of 0.88 (95% confidence interval 0.68 to 1.14) [s1]. It also made no meaningful difference to the need for later bypass surgery (risk ratio 0.99) or repeat stenting (risk ratio 0.86, 95% confidence interval 0.63 to 1.19) [s1].

Why the death-rate signal is soft

An older generation of cardiac-rehab trials, run before modern secondary prevention was routine, suggested a clearer mortality benefit. The updated pooled estimate no longer does, and the most likely reason is not that rehabilitation stopped working but that there is less room left for it to work: when almost every patient already receives drugs and revascularisation that cut the risk of death, the additional mortality effect of an exercise programme becomes small and hard to detect in trials followed for only a year [s1]. What the exercise adds most clearly, in that setting, is fewer recurrent events and fewer trips back to hospital — outcomes that matter to patients and to health systems even where a survival gain cannot be demonstrated [s1].

That distinction is why guidelines still endorse it. The 2023 American Heart Association and American College of Cardiology guideline for chronic coronary disease gives cardiac rehabilitation a Class 1 recommendation — its strongest tier — for eligible patients, on the strength of its effect on symptoms, functional capacity, quality of life and hospitalisation rather than on a promise of longer life [s2].

What it means for a reader

The honest framing is that cardiac rehabilitation is well worth doing and is undersold when it is marketed purely as a way to live longer: the durable, high-certainty findings are fewer heart attacks and fewer hospital admissions, not a proven survival benefit within a year [s1]. The evidence is also thinnest for the groups least represented in the trials, particularly women [s1]. The programme's value sits alongside the rest of secondary prevention rather than replacing it — the same logic that governs decisions about whether to stop beta blockers after a heart attack, and it is the outcome that newer home-based, wearable-guided rehab models and the 2026 European guidance on rehabilitation in heart failure and kidney disease are trying to widen access to. None of this is medical advice about an individual's recovery plan, which belongs with a treating clinician.