Does quitting still help after coronary heart disease is diagnosed?

01

This is not the ‘first heart attack’ timeline

The relevant comparison starts with people already diagnosed with CHD who were smoking: some later stop, while others continue. It does not compare a person after a heart attack with a never-smoker who has never had heart disease. A general headline about risk falling after one smoke-free year therefore cannot be used as a date when an existing coronary condition disappears.

Three outcomes also need separate names. All-cause death counts deaths from any cause; cardiovascular death counts deaths attributed to the heart or blood vessels. A combined event outcome can include fatal and non-fatal events. Fewer events in a group does not establish disappearance of angina, a normal scan or permission to stop follow-up.

[1][2]

02

What the later Cochrane review actually compared

The 2022 Cochrane review included 68 studies with 80,702 participants and searched evidence through April 15, 2021. Eligible adults had CHD, smoked at diagnosis or study baseline, and were followed for at least six months. Importantly, the review compared subsequent smoking status. Even data originating in randomized trials were analysed as cohorts of quitters and continuing smokers; people were not randomly assigned to keep smoking.

Its estimate for cardiovascular death had moderate certainty, while the major adverse cardiovascular event (MACE) estimate had low certainty. The review defined MACE as cardiovascular death, non-fatal myocardial infarction and non-fatal stroke, although definitions differed in some included studies. These estimates favor stopping, but initial disease severity, other preventive treatment and differences between people who quit and continue make the exact magnitude less secure. That is compatible with an established overall benefit; it is not proof that every estimate is equally precise.

[2]

03

Read a hazard ratio without making it your probability

The table shows pooled hazard ratios (HRs), each comparing quitters with people who continued smoking after a coronary diagnosis. During follow-up, an HR compares how quickly an event occurs among people who have not yet had that event; it is not the cumulative proportion who experience it. Below 1 means a lower event rate in the quitting group. An HR of 0.61 is not a 61% personal chance of dying, and the difference from 1 is not a reduction of 39 percentage points.

Different studies followed different populations for different lengths of time. The review's minimum six-month follow-up is an inclusion rule, not a six-month recovery deadline. Nor should cardiovascular death and MACE be added together: a cardiovascular death may already be part of the combined outcome. These are alternative ways of counting outcomes, not separate benefits to total on a calculator.

[2]

04

Connect cessation support to the care already in place

A useful question for the clinician is: ‘How can smoking-cessation support fit into my existing coronary follow-up?’ Current coronary-disease guidance includes cessation support alongside clinical care; the group findings do not authorize changing heart medicines, choosing a cessation medicine or deciding exercise limits. Discuss new or changing concerns with the team responsible for your care rather than assuming a smoke-free milestone has resolved them; this page does not assess symptoms or make a diagnosis.

In England, the NHS links to local stop-smoking services. Ask the service about access and tell the clinician providing your heart care that you are seeking support. Elsewhere, use an appropriate local service. There is no need to submit a diagnosis, medicine list or quit date here; research numbers and your individual care plan remain different things.

[3][4][5]

05

What to keep in mind

• An established coronary diagnosis does not make stopping smoking pointless.
• A quit-versus-continue estimate is not a return to a never-smoker's baseline.
• Cessation support belongs alongside coronary care, not in place of it.