J-curve - myth or reality?

Abstract

Fundamental purpose of therapy in hypertensive patients is reduction of blood pressure and prevention of cardiovascular morbidity and mortality associated with hypertension. Despite many achievements in hypotensive therapy hypertensive patients are still at increased risk of cardiovascular morbidity and mortality. Reasonable is affirmation that intensive therapy will bring more benefits in this group of patients. However there is J curve theory suggesting, that excessive drop of blood pressure, below certain level can increase cardiovascular risk, especially in hypertensive patients with coronary heart disease. Discussion about existence of J curve relationship has lasted for near 25 years, still raising many doubts, which have been initiated by Steward and Cruickshank publications. Despite numerous criticism of research suggesting harmful capability of excessive blood pressure reduction, J curve relationship still remains unsolved. Prospective studies in the late ‘80 and in ‘90 which were conducted to give final explanation of J curve theory and supply answers how far in clinical practice we should lower blood pressure to achieve maximal benefit of hypotensive thrapy. HOT study was the research everybody hoped will explain J curve problem. However, authors did not reach the answer concerning J curve relationship between blood pressure reduction and cardiovascular risk. Analysis of results of INVEST study has supplied apologists of this theory next arguments confirming J curve existence which were presented by Franz Messerli on this years Congress of American Society of Cardiology.
So after analysis of many clinical trials especially INVEST study the conclusion that excessive blood pressure reduction among hypertensive patients with coronary heart disease may increase risk of myocardial infarction seems to be reasonable.