Treatment of mild hypertension with diuretics. The importance of ECG abnormalities in the Oslo Study and in MRFIT.

The Multiple Risk Factor Intervention Trial (MRFIT) showed that diuretic treatment of hypertensive men with certain ECG abnormalities at entry was associated with an increased coronary heart disease mortality in the special-intervention group as compared with the usual-care group. Following the same criteria for resting ECG abnormalities as in MRFIT, The Oslo Study trial of mild hypertension has been reanalyzed for similar effects. Although numbers of first coronary events are low in this study (20 cases in the treated group and 13 in the control group), similar trends are present in The Oslo Study. The excess of seven cases of coronary events in the Oslo treatment group can mainly be explained by introduction of the MRFIT ECG-Minnesota codes.