Angiotensin receptor blockers (ARBs) are as effective as angiotensin-converting (ACE) inhibitors at preventing cardiovascular events in the first line treatment of hypertension, but have a better safety profile, research suggests.

International guidelines recommended either therapy for patients starting blood pressure treatment for the first time, although ACE inhibitors tended to be more commonly prescribed, the US researchers wrote in Hypertension.

Yet there had been few head-to-head studies of the drugs and those that did exist had conflicting results.

In a large-scale propensity-matched network study, researchers analysed records from eight international electronic health and insurance databases, containing information on almost 3 million people who had started therapy with either an ARB or an ACE inhibitor.

They found no statistically significant difference between the two therapies for rates of acute myocardial infarction, heart failure, stroke, or a composite cardiovascular event endpoint that included the previous three events and sudden cardiac death.

However, they found patients taking ACE inhibitors were 3.3 times more likely to experience angioedema, 32% more likely to experience acute pancreatitis, 32% more likely to develop a cough and 18% more likely to develop gastrointestinal bleeding.

‘The effect of ACE inhibitors on preventing degradation of bradykinin is well known, so our findings of significantly increased risk of angioedema and cough in patients on ACE inhibitors are both expected and mechanistically plausible,’ they wrote.

The association between ACE inhibitors and pancreatitis has been previously reported, primarily in case reports, but the association with gastrointestinal bleeding could be a novel finding, they said with little previous evidence on this topic.

‘While current US and European guidelines consider ACE inhibitors and ARBs to be equally recommended first-line therapies and other international guidelines group ACE inhibitors and ARBs together as a single treatment category, these results lend further support to recent calls for the differentiation and elevation of ARBs as first-line therapy over ACE inhibitors in the treatment of hypertension,’ the researchers wrote.

‘Our findings support preferentially starting ARBs rather than ACE inhibitors for patients and providers who intend to treat hypertension through renin-angiotensin system inhibition.’

Most of the participants taking ACE inhibitors (80%) were taking lisinopril, and the most used ARB (45% of those taking this type of medication) was losartan.

Results might not be applicable to patients who were taking multiple therapies, had already started therapy, or were switching medications, the researchers cautioned.

It comes after research found that the benefits of statins for primary CVD prevention outweigh a small risk of adverse events.