Hemodynamic and pathophysiological characteristics of intradialytic blood pressure elevation in patients with end-stage renal disease.

An increase in systolic blood pressure (SBP) after hemodialysis (intradialytic-HTN) is associated with adverse outcomes in patients on regular hemodialysis. However, the hemodynamic and Doppler echocardiographic characteristics of intradialytic-HTN and its impact on clinical outcomes are unclear. A retrospective analysis of 84 patients (45 men, 70±9 years) stratified into three groups on the basis of SBP response from pre- to post-hemodialysis: GHTN (intradialytic-HTN, SBP increase 10 mm Hg), GDROP<15 mm Hg (SBP drop <15 mm Hg), and GDROP15 mm Hg (SBP drop 15 mm Hg). Hemodynamic and echocardiographic assessments were performed pre- and post-hemodialysis, and patients were followed for 41±17 months. GHTN had higher blood glucose and lower baseline SBP, serum potassium and total cholesterol. Cardiothoracic ratio was smaller, and peak early diastolic mitral annular velocity (E') was lower in GHTN. During hemodialysis, SBP and diastolic blood pressure increased only in GHTN. After hemodialysis, left ventricular (LV) filling pressure (E/E' ratio) decreased only in GDROP15 mm Hg, resulting in a higher E/E' ratio in GHTN than GDROP15 mm Hg. Multivariate logistic regression analysis revealed a positive correlation between blood glucose and intradialytic-HTN, whereas cardiothoracic ratio, pre-hemodialysis SBP and the change in E/E' ratio with hemodialysis were negatively related to intradialytic-HTN. During follow-up, GHTN had more cardiovascular deaths than GDROP15 mm Hg (P=0.03). Multivariate Cox regression analysis showed that lower serum potassium and previous coronary artery disease, but not intradialytic-HTN, were associated with cardiovascular deaths. A higher LV afterload and elevated filling pressures after hemodialysis, indicative of increased cardiovascular stiffening and impaired diastolic filling, may contribute in part to an increased cardiovascular burden in patients with intradialytic-HTN.