Proton pump inhibitors exert no effect on acute MI risk
Proton pump inhibitors do not appear to contribute to an increase in the risk of acute myocardial infarction (MI) compared with histamine-2 receptor antagonists (H2RAs), a study has shown.
Researchers followed more than 5 million new users of prescription PPIs and H2RAs for the development of MI. Median follow-up time was 60 days for patients with commercial insurance and 96 days for those with Medicare Supplemental insurance. Kaplan-Meier methods were applied to estimate the risk of MI at 3, 12 and 36 months after treatment initiation.
Results revealed the 12-month weighted risk of MI to be low overall, with approximately 2 cases per 1,000 among patients in commercial plans and 8 per 1,000 among patients in Medicare Supplemental plans.
When the risk difference (RD) was analysed, no significant difference in MI risk was seen between patients who started PPIs vs H2RAs for the first 12 months, either in the commercial population (weighted RD per 1,000, –0.08; 95 percent CI, –0.51 to 0.36) or the Medicare Supplemental population (weighted RD per 1000, –0.45;–1.53 to 0.58).
The present data indicate that physicians and patients should not avoid starting a PPI because of concerns related to MI risk, according to researchers.
The mechanism responsible for the effect of PPIs on MI is hypothesized to involve the altered vascular reactivity, as the drugs have been reported to inhibit dimethylarginine dimethylaminohydrolase. This leads to the blockade of vascular nitric oxide synthase activity and enhanced contractivity with loss of normal relaxation. [Gastroenterology 2015;149:830–833]