[Hypertension, coronary heart disease and stroke: should the blood pressure J-curve be a concern?].
The paradoxical increase in cardiovascular events in patients with treatment-induced low blood pressure (BP), particularly in hypertensives with pre-existing coronary artery disease, especially those with critically low diastolic BP, which conflicts with data from epidemiologic observational studies, is referred to as a J-curve. It was first described over 30 years ago and is still the subject of considerable controversy. Recent large clinical outcomes trials (INVEST, TNT, ONTARGET, PROVE IT-TIMI 22, SMART) and meta-analyses strongly support its existence for systolic and diastolic BP. The diastolic J-curve is commonly more pronounced. In contrast to cardiovascular complications related to coronary artery disease, no J-curve phenomenon was noted for stroke in most of these studies. This is explained by differences in cerebral and coronary autoregulation and because coronary perfusion occurs only during diastole. On the basis of this review, we suggest a cautious, individualized approach to treatment, particularly in hypertensive patients with coronary heart disease or high risk for impaired coronary blood flow. In these patients we advise against treatment that lowers systolic BP below 120-125 mmHg and, particularly, diastolic BP below 70-75 mmHg.
Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal. jnogueira@fm.ul.pt
José Braz
JB
Nogueira
D001794:Blood Pressure; D003327:Coronary Disease / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000503:physiopathology*