A new multinational study shows that the most popular first-line treatment for hypertension is less effective and causes more side effects than a prescribed alternative much less often.
Researchers, including George Hripcsak of Columbia, MD, and Patrick Ryan, Ph.D., analyzed electronic health records and claims data from nearly 5 million patients who had started medical treatment for hypertension. They found that patients who were first prescribed thiazide diuretics had 15% fewer heart attacks, heart attacks, and hospitalizations for heart failure than patients who had prescribes ACE inhibitors. Patients who started with thiazide diuretics also had fewer side effects.
The researchers estimated that about 3,100 major cardiovascular events among patients who took ACE inhibitors for the first time could have been avoided if they had first been treated with a thiazide diuretic.
The study – the most comprehensive to compare results in newly treated hypertensive patients – was published in The lancet.
Little evidence to guide drug selection
Current guidelines from the American College of Cardiology and the American Heart Association recommend starting antihypertensive therapy with any drug of five different classes of drugs, including thiazide diuretics, inhibitors of ACE, angiotensin II receptor antagonists (ARBs), calcium channel blockers of dihydropyridine and calcium channel blockers of dihydropyridine.
However, there is little evidence to help physicians decide which class of drugs to start with: the literature contains randomized, controlled clinical trial data of only 31,000 patients – and none of them was just starting antihypertensive treatment. As a result, most clinical guidelines rely on the opinion of experts rather than on data.
"Randomized clinical tests George Hripcsak, MD, president of Biomedical Informatics of the College of Physicians and Surgeons Vagelos of Columbia University and author of the study. "But they are not good at making comparisons among several classes of drugs in a diverse group of patients that you met in the real world"
Observational studies can be used to detect effects that may not have been apparent in randomized trials. But many are too small to draw meaningful conclusions or suffer from other types of distortion.
"Unintentionally or not, journals and authors tend to publish studies that yield interesting results, and researchers may even select analytical methods that best fit to get the results that fit their assumptions, "says Hripcsak." This is an exercise in selecting results, which makes the results less reliable. "
Read this article to learn more about biases in observational studies.
Solution: Big Data
To address these issues, researchers analyzed data from millions of patient health records and considered tens of thousands of different variables, essential to eliminate confounders. This method, known as LEGEND, was created by a consortium of scientists participating in the OHDSI (Observational Health Data Science Initiative) network. By using LEGEND, researchers can share methodology and standardize data, minimizing bias.
"LEGEND provides a systematic framework that can reproducibly generate evidence by applying advanced analytics across a network of disparate databases for a wide range of exposures and outcomes," said Patrick Ryan, Ph.D. , Assistant Professor of Biomedical Informatics at Columbia University, Vagelos. College of Physicians and Surgeons and Vice President, Observational Health Data Analysis, Janssen Research and Development. "Not only does LEGEND provide a way to meet the real needs of the healthcare community, but it also provides complementary diagnostics to help us understand how much we can trust the evidence we have produced."
The current study analyzed claims and electronic health records of 4.9 million patients in four countries who were starting antihypertensive therapy with a single drug. The researchers used a complex algorithm to identify the number of heart attacks, hospitalizations for heart failure, stroke, and nearly 50 drug side effects that occurred in patients taking one of the first line antihypertensives. They also used a number of techniques designed to minimize bias and account for about 60,000 different variables.
The study found that ACE inhibitors were the first antihypertensive drug prescribed for 48% of patients, compared to 17% of patients who had been prescribed thiazide diuretics. Patients initially treated with thiazide diuretics had 15% fewer heart attacks, hospitalizations for cardiac arrest, and stroke compared to those treated with other first-line therapies. In addition, patients treated for the first time with ACE inhibitors had a rate of adverse events greater than 19 compared to thiazide users.
The study also found that non-dihydropyridic calcium channel blockers were less effective than all other classes of first-line drugs.
"With LEGEND, we found a way to fill in the gaps left by randomized controlled trials and to help physicians make clinical decisions," said Hripcsak.
The document, "Overall Comparative Effectiveness and Safety of First Line Antihypertensives" drug classes: a systematic, multinational and large-scale analysis ", was published in The lancet.
Irving Medical Center at Columbia University
Most prescribed blood pressure medications may be less effective than others (2019, October 24)
recovered on October 25, 2019
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