Cardiac oxygen supply is compromised during the night in hypertensive patients

The enhanced heart rate and blood pressure soon after awaking increases cardiac oxygen demand, and has been associated with the high incidence of acute myocardial infarction in the morning. The behavior of cardiac oxygen supply is unknown. We hypothesized that oxygen supply decreases in the morning and to that purpose investigated cardiac oxygen demand and oxygen supply at night and after awaking. We compared hypertensive to normotensive subjects and furthermore assessed whether pressures measured non-invasively and intra-arterially give similar results. Aortic pressure was reconstructed from 24-h intra-brachial and simultaneously obtained non-invasive finger pressure in 14 hypertensives and 8 normotensives. Supply was assessed by Diastolic Time Fraction (DTF, ratio of diastolic and heart period), demand by Rate-Pressure Product (RPP, systolic pressure times heart rate, HR) and supply/demand ratio by Adia/Asys, with Adia and Asys diastolic and systolic areas under the aortic pressure curve. Hypertensives had lower supply by DTF and higher demand by RPP than normotensives during the night. DTF decreased and RPP increased in both groups after awaking. The DTF of hypertensives decreased less becoming similar to the DTF of normotensives in the morning; the RPP remained higher. Adia/Asys followed the pattern of DTF. Findings from invasively and non-invasively determined pressure were similar. The cardiac oxygen supply/demand ratio in hypertensive patients is lower than in normotensives at night. With a smaller night-day differences, the hypertensives’ risk for cardiovascular events may be more evenly spread over the 24 h. This information can be obtained noninvasively

Serial hemodynamic measurement in normal pregnancy, preeclampsia, and intrauterine growth restriction

OBJECTIVE: The study hypothesis was that hemodynamic measurements in conjunction with uterine artery Doppler could enable selection of women at risk for the development of preeclampsia or fetal growth restriction. STUDY DESIGN: Systolic (SBP) and diastolic blood pressure, heart rate (RR), cardiac output (CO), total peripheral resistance (TPR), phase difference of SBP and RR interval were measured serially before, during, and after pregnancy. At 20 weeks, uterine artery Doppler measurement was performed. Outcome was classified as preeclampsia (PE) or gestational hypertension (GH) with or without fetal growth restriction (FGR), FGR without PE or GH, and normal pregnancy (NP). Differences between these groups were assessed by 1-way analysis of variance and discriminant analysis. RESULTS: In early pregnancy, in comparison with NP (n = 28), PE/GH had a higher SBP and phase difference of SBP-RR interval. CO was higher in PE/GH without FGR (n = 5) but not PE/GH with FGR (n = 5). FGR, either with or without PE/GH (n = 4), was associated with higher TPR. Conjunction with uterine Doppler allowed selection of 93% of women with an abnormal outcome with a specificity of 100%. CONCLUSION: The study supports our hypothesis that in early pregnancy, hemodynamic parameters differ from normal in women predisposed to develop preeclampsia or fetal growth restrictio

African Ancestry vs. Creatine Kinase to Predict Hypertension Control: Time for a Change?

Background: African ancestry patients are considered separately in hypertension guidelines because of more severe hypertension that is presumably harder to control. However, despite the perceived benefit in reducing health disparities, racial profiling in medicine is increasingly criticized for its potential of bias and stereotyping. Therefore, we studied whether creatine kinase (CK), an ATP-regenerating enzyme that enhances vascular contractility and sodium retention, could serve as a more proximate causal parameter of therapy failure than race/ancestry. Methods: In a random multiethnic population sample, we compared the performance of African ancestry vs. resting plasma CK as predictors of treated uncontrolled hypertension. Difference in area under the receiver operating curve (AUC) was the primary outcome. Results: We analyzed 1,405 persons of African, Asian, and European ancestry (40.2% men, mean age 45.5 years, SE 0.2). Hypertension prevalence was 39% in African vs. 29% in non-African ancestry participants vs. 41% and 27% by high and low CK tertiles. Control rates of treated patients were similar by ancestry (African ancestry patients 40%, non-African ancestry 41%; P = 0.84), but 27% vs. 53% in patients with high vs. low CK (22% vs. 67% in African and 32% vs. 52% in non-African participants). AUC was 0.51 [0.41-0.60] for African ancestry vs. 0.64 [0.55-0.73] for log CK (P = 0.02). Conclusions: In contrast to African ancestry, CK might identify hypertensive patients at risk for therapy failure across different ancestry groups. Larger, prospective studies should establish whether resting plasma CK is clinically useful as an impartial method to help predict antihypertensive therapy failure

Systematic review: Antihypertensive drug therapy in black patients

Background: Hypertension occurs more frequently and is generally more severe in black persons than in white persons, leading to excess morbidity and mortality. Purpose: To systematically review the efficacy of different anti-hypertensive drugs in reducing blood pressure, morbidity, and mortality in hypertensive black adults. Data Sources: The following databases were searched from their inception through November 2003: MEDLINE, EMBASE, LILACS (Literatura Latino-Americana y del Caribe en Ciencias de la Salud), African Index Medicus, and the Cochrane Library. PubMed was also searched from September 2003 through March 2004. Searches were conducted without language restriction. Study Selection: Randomized, controlled trials of drugs versus placebo (blood pressure outcomes) or drugs versus placebo or other drugs (morbidity and mortality outcomes). Data Extraction: 2 reviewers independently extracted data. Data Synthesis: The efficacy of beta-blockers in reducing systolic blood pressure and the efficacy of angiotensin-converting enzyme inhibitors in achieving diastolic blood pressure goals did not significantly differ from that of placebo (weighted mean difference for beta-blockers, -3.53 mm Hg [95% CI, -7.51 to 0.45 mm Hg]; relative risk for angiotensin-converting enzyme inhibitors, 1.35 [CI, 0.81 to 2.26]). In the pooled analyses, other reviewed drugs (calcium-channel blockers, diuretics, central sympatholytics, alpha-blockers, and angiotensin II receptor blockers) were more effective than placebo in reducing blood pressure, but only calcium-channel blockers remained effective in all prespecified subgroups, including patients with a baseline diastolic blood pressure of 110 mm Hg or greater. Main morbidity and mortality outcomes did not differ significantly between treatment groups when drugs were combined to reach blood pressure goals. However, trial results indicated a greater occurrence of diabetes with diuretics and a higher risk for cardiovascular events with drug regimens that included angiotensin-converting enzyme inhibitors. Limitations: This meta-analysis evaluated the blood pressure lowering-efficacy of monotherapy only. Conclusions: Drugs differ in their efficacy for reducing blood pressure in black patients, but there is no solid evidence that efficacy for reducing morbidity and mortality outcomes differs once patients achieve the blood pressure goa