Elevated BP at home but not in clinic can indicate increased heart attack risk

Researchers have found that patients with masked hypertension, or normal BP in clinic but elevated BP when measured at home, had an increased risk of death and cardiovascular events compared with those who had normal BP in both clinic and at home.

The analysis included 5008 participants. While self-measured home BP was lower on average than clinic BP (mean home systolic BP 7.0 mm Hg and diastolic BP 3.0 mm Hg lower than the conventional blood pressure), 67 (5.0 per cent) of those with optimal clinic BP (less than 120/80 mm Hg), 187 (18.4 per cent) of those with normal clinic BP (120/80 mm Hg), and 315 (30.4 per cent) of those with high-normal clinic BP (130/85 mm Hg) had masked hypertension, or BP greater than 130/85 when BP was measured at home.

During a median of 8.3 years (total of 46,593 person-years) of follow-up, 522 participants died and 414 had a fatal or nonfatal cardiovascular event.

Compared with patients with optimal blood pressure without masked hypertension, multivariable-adjusted hazard ratios for total mortality for those with optimal clinic BP but masked hypertension were 2.21 (CI, 1.27.85); for those with normal clinic BP but masked hypertension, 1.57 (CI, 1.02.41); and for those with high-normal clinic BP but masked hypertension, 1.54 (CI, 1.07.23).

The authors found that patients with masked hypertension were more likely to be male, to smoke, to have diabetes mellitus or a history of cardiovascular disease, and to be older and more obese.