After quitting, do blood vessels recover? Read FMD, PWV and AIx separately

01

One percentage point of FMD is not one percentage point of heart-attack risk

In Johnson’s 2010 study, 1,504 smokers entered; 923 returned at one year and 334 were classified as abstinent. Classification used the previous seven days’ self-report plus exhaled carbon monoxide, not proof of a continuously smoke-free year. Their mean FMD rose from 6.2% to 7.2%: approximately one percentage point of diameter response. Continuing smokers’ means were 6.5% and 6.6%, with no statistically clear change.

Treatment allocation was random, but who actually quit was not. Moreover, 38.6% did not return for the FMD visit; there was no never-smoker control, and measurements were taken only at baseline and one year. The study cannot establish a normal value regained, a first-week recovery date or an individual reduction in heart attacks.

[2]

02

Check what ‘cessation’ meant before trusting a review headline

George’s 2026 review included 23 studies with 11,702 participants, mixing stopping cigarettes with switching exclusively to e-cigarettes. It used narrative synthesis rather than a pooled effect estimate because methods and populations differed. In its evidence table, the moderate-certainty FMD evidence from three randomized trials included two switching trials. In one, the continuing-smoking comparison group was not randomly allocated. That rating is not a rating for pure cessation alone.

Certainty for PWV and AIx was very low. Different arterial segments, follow-up times, abstinence definitions and accompanying treatments matter. A result from switching products cannot be silently relabelled stopping nicotine, nor does this review establish product safety, equivalence or a recommended substitute.

[1]

03

A three-year study shows why the measures need not agree

In Schmidt’s study, 848 of 1,417 participants returned at year three, including 212 classified as abstinent using recent seven-day smoking status and carbon monoxide. AIx was more favourable in abstainers after accounting for the starting AIx, but their raw mean did not fall. PWV showed no statistically clear smoking-status difference. After accounting for additional characteristics and changes such as blood pressure, AIx was no longer clearly associated with smoking status either.

Loss to follow-up, changing medication and other differences limit interpretation. These findings do not show that quitting harms arteries; they show why ‘every vascular marker improves together’ is too strong. Neither this analysis nor the one-year FMD analysis counted clinical events as its vascular outcome.

[3]

04

Ask which outcome a claim describes

For an existing vascular result or health concern, ask a qualified clinician: ‘Is this about a dilation response, wave stiffness or actual clinical events—and is the comparison relevant to me?’ Interpretation, testing and care remain individual clinical decisions, not a countdown here. Separately, NHS local stop-smoking services provide support in England. No blood-pressure value, scan or smoking history needs to be entered on this page.

[2][3][4]

05

What to keep in mind

• Name the measurement before interpreting improvement.
• Separate cigarette cessation from product switching.
• A group marker change is not a personal event forecast.