The concept of treatment of hypertension has gone through wide swings over the years.From ignoring blood pressure(BP)treatment initially,to aggressive BP control recently.As newer and more effective drugs were develop...The concept of treatment of hypertension has gone through wide swings over the years.From ignoring blood pressure(BP)treatment initially,to aggressive BP control recently.As newer and more effective drugs were developed,it was possible to lower BP to very low levels.However,recent studies have shown that aggressive BP control might not be in the best interest of the patient.Low levels of diastolic BP(DBP)have been associated with increased cardiovascular events, a situation known as the J-curve effect.This has been seen mostly with low DBP,since the coronary arteries are perfused during the diastolic phase of the cardiac cycle.Due to an autoregulatory mechanism,the heart is protected against wide fluctuations of BP.However, the presence of coronary heart disease,hypertension, especially with left ventricular hypertrophy,shift the curve to higher BP levels and makes the heart more liable to DBP fluctuations.The J-Curve effect has been reported by most investigators,but not by others.Recently,a J-Curve effect has been observed with systolic BP(SBP),as well.In contrast to the heart,the brain is very infrequently subjected to J-curve effect,and in contrast to the heart,the brain's blood flow autoregulation depends mostly on the SBP.A Medline search of the English literature on this subject was conducted between 1992 and 2010 and 11 pertinent articles were selected.These articles with collateral literature will be discussed in this concise review.展开更多
Reduction of diastolic blood pressure to less than 60-80 mm Hg does not improve mortality and may lead to adversecardiovascular events in high risk patient populations. Despite a growing body of evidence supporting th...Reduction of diastolic blood pressure to less than 60-80 mm Hg does not improve mortality and may lead to adversecardiovascular events in high risk patient populations. Despite a growing body of evidence supporting the J-curve phenomenon, no major society guidelines on hypertension include a lower threshold target for diastolic blood pressure. Many major society guidelines for hypertension have been updated in the last 5 years. Some guidelines include goals specific to age and co-morbid conditions. The Sixth Joint Task Force of the European Society of Cardiology and the Canadian Hypertension Education Program are the only guidelines to date that have recommended a lower threshold target, with the Canadian guidelines recommending a caution against diastolic blood pressure less than or equal to 60 mm Hg in patients with coronary artery disease. While systolic blood pressure has been proven to be the overriding risk factor in hypertensive patients over the age of 50 years, diastolic blood pressure is an important predictor of mortality in younger adults. Post hoc data analysis of previous clinical trials regarding safe lower diastolic blood pressure threshold remains inconsistent. Randomized clinical trials designed to determine the appropriate diastolic blood pressure targets among different age groups and populations with different comorbidities are warranted. Hypertension guideline goals should be based on an individual's age, level of risk, and certain co-morbid conditions, especially coronary artery disease, stroke, chronic kidney disease, and diabetes.展开更多
文摘The concept of treatment of hypertension has gone through wide swings over the years.From ignoring blood pressure(BP)treatment initially,to aggressive BP control recently.As newer and more effective drugs were developed,it was possible to lower BP to very low levels.However,recent studies have shown that aggressive BP control might not be in the best interest of the patient.Low levels of diastolic BP(DBP)have been associated with increased cardiovascular events, a situation known as the J-curve effect.This has been seen mostly with low DBP,since the coronary arteries are perfused during the diastolic phase of the cardiac cycle.Due to an autoregulatory mechanism,the heart is protected against wide fluctuations of BP.However, the presence of coronary heart disease,hypertension, especially with left ventricular hypertrophy,shift the curve to higher BP levels and makes the heart more liable to DBP fluctuations.The J-Curve effect has been reported by most investigators,but not by others.Recently,a J-Curve effect has been observed with systolic BP(SBP),as well.In contrast to the heart,the brain is very infrequently subjected to J-curve effect,and in contrast to the heart,the brain's blood flow autoregulation depends mostly on the SBP.A Medline search of the English literature on this subject was conducted between 1992 and 2010 and 11 pertinent articles were selected.These articles with collateral literature will be discussed in this concise review.
文摘Reduction of diastolic blood pressure to less than 60-80 mm Hg does not improve mortality and may lead to adversecardiovascular events in high risk patient populations. Despite a growing body of evidence supporting the J-curve phenomenon, no major society guidelines on hypertension include a lower threshold target for diastolic blood pressure. Many major society guidelines for hypertension have been updated in the last 5 years. Some guidelines include goals specific to age and co-morbid conditions. The Sixth Joint Task Force of the European Society of Cardiology and the Canadian Hypertension Education Program are the only guidelines to date that have recommended a lower threshold target, with the Canadian guidelines recommending a caution against diastolic blood pressure less than or equal to 60 mm Hg in patients with coronary artery disease. While systolic blood pressure has been proven to be the overriding risk factor in hypertensive patients over the age of 50 years, diastolic blood pressure is an important predictor of mortality in younger adults. Post hoc data analysis of previous clinical trials regarding safe lower diastolic blood pressure threshold remains inconsistent. Randomized clinical trials designed to determine the appropriate diastolic blood pressure targets among different age groups and populations with different comorbidities are warranted. Hypertension guideline goals should be based on an individual's age, level of risk, and certain co-morbid conditions, especially coronary artery disease, stroke, chronic kidney disease, and diabetes.
