The analysis was performed on patients with metabolic syndrome, defined as hypertension and at least two of the following:
- Body Mass Index greater than 30kg/M2
- Fasting glucose greater than 5.6mmol/L
- Triglycerides greater than 1.7mmol/L
- HDL less than 1.0mmol/L for a man and 1.3mmol/L for a woman
The analysis compared all four study drugs (chlorthalidone, amlodipine, lisinopril and doxazosin) and also studied black and non-black patients in separate groups.
The analysis found significantly higher rates of heart failure for all drugs and irrespective of ethnicity when compared to the chlorthalidone. There was also an increased risk of combined cardiovascular disease for the lisinopril and doxazosin groups irrespective of ethnicity. Finally, there was a higher stroke rate in black patients in the lisinopril and doxazosin groups and end-stage renal disease in black patients in the lisinopril group.
The authors conclude that, "the ALLHAT findings fail to support the preference for calcium channel blockers, alpha-blockers, or angiotensin-converting enzyme inhibitors compared with thiazide-type diuretics".
Action: This analysis adds weight to the positioning of thiazides as first line antihypertensives in the vast majority of patients with hypertension. Clinicians should consider their current practice in comparison to the recommendations made by the National Institute of Health and Clinical Excellence.