In the very interesting case-control study by Klungel et al,1 we noted 2 intriguing observations about which we would like to comment: (1) among patients without cardiovascular complication treated with monotherapy, the risk ratio (RR) for ischemic stroke was much higher in those treated with calcium antagonist alone (RR, 2.30; 95% confidence interval [CI], 1.16-4.56) compared with those treated with thiazide alone; (2) among patients treated with 1 or 2 drugs, the risk of ischemic stroke associated with no thiazide treatment compared with thiazide treatment was remarkably higher in those with clinically recognized cardiovascular disease than in those without this complication (RR, 1.85 vs 1.25; 95% CI, 1.26-2.71 vs 0.87-1.80).
Fournier A, Oprisiu R, Achard JM. Differences Between Primary vs Secondary Prevention Trials Regarding the Stroke Protective Effect of Antihypertensive Drugs. Arch Intern Med. 2001;161(17):2152-2153. doi: