Angiotensin-converting enzyme (ACE) inhibitors are less effective for the treatment of hypertension compared with thiazide diuretics as they have a worse safety profile, a study published in The Lancet has found.
The research, conducted at Columbia University in New York and published on 24 October 2019, compared the two treatments by looking at electronic health records and other insurance claims databases across four countries — Germany, Japan, South Korea and the United States — to collect information on 5 million patients who had started treatment for hypertension.
Researchers found that patients prescribed thiazide diuretics in the first instance had 15% fewer heart attacks, hospitalisations for heart failure, and strokes compared with those treated with other first-line therapies.
The authors said that starting patients on thiazide diuretics instead of ACE inhibitors could, therefore, have “a substantial public health impact”.
“If the 2.4 million ACE inhibitors’ new users had instead started on a thiazide or thiazide like diuretic, more than 3,100 major cardiovascular events could potentially have been avoided,” they added.
The research findings come despite ACE inhibitors being the most commonly prescribed first-line treatment for hypertension among the patients studied, with 48% of patients prescribed the drug in the first instance, compared to 17% who were first prescribed thiazide diuretics.
According to prescription cost analysis data published by NHS Digital in March 2019, more than 44.1 million ACE inhibitors were dispensed in the community in England in 2018, compared with more than 14.6 million thiazides and related diuretics.
In addition to reducing the number of cardiovascular events, the research found that patients first treated with ACE inhibitors had higher rates of 19 side effects compared with thiazide users, such as mortality, gastrointestinal side effects and renal disorders.
Guidance from the National Institute for Health and Care Excellence (NICE) was updated on 28 August 2019 to lower the threshold for people who should start on hypertensive treatment to include patients aged under 80 years with stage-one hypertension and a cardiovascular risk above 10%.
NICE recommends prescribing patients an ACE inhibitor or an angiotensin-II receptor blocker if they “have type 2 diabetes [mellitus (T2DM)] and are of any age or family origin … or are aged under 55 [years], but not of black African or African–Caribbean family origin”.
Patients aged 55 years or over who do not have T2DM, or patients of any age who are of black African or African–Caribbean family origin and do not have T2DM should be offered a calcium-channel blocker (CCB), the recommednation continues.
These patients are then recommended “a thiazide-like diuretic” if a CCB is not tolerated or “there is evidence of heart failure”.
The researchers also found that non-dihydropyridine CCBs were less effective than all other first-line drug classes.