2020 International Society of Hypertension Guidelines: preference of calcium channel blocker over thiazide-like diuretics lacks evidence

Comparison between the world health organization (WHO) and international society of hypertension (ISH) guidelines for hypertension

The global burden of hypertension remains an unsolved problem, especially in low- and middle-income countries (LMICs). For this reason, clinical practice guidelines containing the latest evidence-based recommendations are crucial in the management of hypertension. It is noteworthy that guidelines simply translated from those of high-income countries (HICs) are not the solution to the problem of hypertension in LMICs. Among the numerous guidelines available, those of the World Health Organisation and the International Society of Hypertension are the latest to be published as of the writing of this article. In this review, we conducted both general and specific comparisons between the recommendations supplied by both guidelines. Differences in aspects of hypertension management such as the timing of antihypertensive initiation, assessment of comorbidities and cardiovascular risk factors, pharmacological therapy selection, and blood pressure target and reassessment are explored. Lastly, the implications of the differences found between the two guidelines in both LMICs and HICs are discussed.Key messagesCurrently, with low treatment and control rates, hypertension remains a burden in low- and middle-income countries (LMICs).The lack of customised guidelines for LMICs cannot be solved simply by adopting guidelines from high-income countries.The World Health Organisation (WHO) recently published a clinical guideline for the pharmacological management of hypertension in LMICs. We compare select recommendations from the guidelines to those published by the International Society of Hypertension.

Effect of Calcium Channel Blockers versus Diuretics for Hypertension

Background

Although calcium channel blockers (CCBs) are recognized as clinical first-line agents for the treatment of hypertension, their use in combination with diuretics in cardiovascular disease caused by hypertension remains controversial.

Methods

We searched the three major databases of the Cochrane Library, EMBASE, and PubMed for the terms “calcium channel blockers,” “thiazide diuretics,” “loop diuretics,” and “hypertension,” “randomized controlled trials” and “meta-analysis trials.” These terms were searched from January 1991 to October 2021.

Results

For the primary outcome, in 5 studies including 35,057 patients, there was no statistically significant difference in all-cause mortality with calcium channel blockers compared with diuretics (RR = 0.98, 95% CI 0.92–1.04, I² = 0). In four studies including 33,643 patients with major cardiovascular events, there was no statistically significant difference in major cardiovascular events with calcium channel blockers compared with diuretics (RR = 1.00, 95% CI 1.04–1.09, I² = 0).

Conclusion

There is no statistically significant difference between calcium channel blockers and diuretics in terms of cardiovascular clinical prognosis in hypertensive patients, but there are positive implications for clinical guidance, which need to be fully validated in new large randomized controlled trials.