Comparison of the prognostic value of dipyridamole and dobutamine myocardial perfusion scintigraphy in hemodialysis patients.

Screening for coronary artery disease (CAD) in hemodialysis patients is hampered by contraindications and/or limitations of the available techniques in this population. Myocardial perfusion scintigraphy (MPS) using dipyridamole has been considered inaccurate due to abnormally high basal levels of adenosine in uremia that could blunt the vasodilatory response. Since dobutamine may be more reliable, we directly compared the two in patients on hemodialysis. We performed MPS at rest and after separate dipyridamole or dobutamine stress in 121 chronic hemodialysis patients. More numerous, larger, and more intense reversible lesions were induced with dobutamine than with dipyridamole, mainly in the anteroseptal segments. Reversibility with dipyridamole but not dobutamine MPS was independently and strongly related with mortality associated with CAD and with fatal and non-fatal CAD. We hypothesize that the chronotropic action of dobutamine induced alterations of wall motion, leading to spurious perfusion defects, not unlike artifacts seen with left bundle branch block. Our study shows that even though dobutamine induced more pronounced myocardial ischemia than dipyridamole in chronic hemodialysis patients, dipyridamole MPS more accurately identifies patients at high risk for subsequent cardiac death or non-fatal CAD than dobutamine.

Prognostic Value of Masked Uncontrolled Hypertension.

The prognostic relevance of masked uncontrolled hypertension (MUCH) is incompletely clear, and its global impact on cardiovascular outcomes and mortality has not been assessed. The aim of this study was to perform a meta-analysis on the prognostic value of MUCH. We searched for articles assessing outcome in patients with MUCH compared with those with controlled hypertension (CH) and reporting adjusted hazard ratio and 95% CI. We identified 6 studies using ambulatory blood pressure monitoring (12 610 patients with 933 events) and 5 using home blood pressure measurement (17 742 patients with 394 events). The global population included 30 352 patients who experienced 1327 events. Selected studies had cardiovascular outcomes and all-cause mortality as primary outcome, and the main result is a composite of these events. The overall adjusted hazard ratio was 1.80 (95% CI, 1.57-2.06) for MUCH versus CH. Subgroup meta-analysis showed that adjusted hazard ratio was 1.83 (95% CI, 1.52-2.21) in studies using ambulatory blood pressure monitoring and 1.75 (95% CI, 1.38-2.20) in those using home blood pressure measurement. Risk was significantly higher in MUCH than in CH independently of follow-up length and types of studied events. MUCH was at significantly higher risk than CH in all ethnic groups, but the highest hazard ratio was found in studies, including black patients. Risk of cardiovascular events and all-cause mortality is significantly higher in patients with MUCH than in those with CH. MUCH detected by ambulatory or home blood pressure measurement seems to convey similar prognostic information.

Prognostic value of ambulatory blood-pressure recordings in patients with treated hypertension.

BACKGROUND: It is uncertain whether ambulatory blood-pressure measurements recorded for 24 hours in patients with treated hypertension predict cardiovascular events independently of blood-pressure measurements obtained in the physician's office and other cardiovascular risk factors. METHODS: We assessed the association between base-line ambulatory blood pressures in treated patients and subsequent cardiovascular events among 1963 patients with a median follow-up of 5 years (range, 1 to 66 months). RESULTS: We documented new cardiovascular events in 157 patients. In a Cox proportional-hazards model with adjustment for age, sex, smoking status, presence or absence of diabetes mellitus, serum cholesterol concentration, body-mass index, use or nonuse of lipid-lowering drugs, and presence or absence of a history of cardiovascular events, as well as blood pressure measured at the physician's office, higher mean values for 24-hour ambulatory systolic and diastolic blood pressure were independent risk factors for new cardiovascular events. The adjusted relative risk of cardiovascular events associated with a 1-SD increment in blood pressure was 1.34 (95 percent confidence interval, 1.11 to 1.62) for 24-hour ambulatory systolic blood pressure, 1.30 (95 percent confidence interval, 1.08 to 1.58) for ambulatory systolic blood pressure during the daytime, and 1.27 (95 percent confidence interval, 1.07 to 1.57) for ambulatory systolic blood pressure during the nighttime. For ambulatory diastolic blood pressure, the corresponding relative risks of cardiovascular events associated with a 1-SD increment were 1.21 (95 percent confidence interval, 1.01 to 1.46), 1.24 (95 percent confidence interval, 1.03 to 1.49), and 1.18 (95 percent confidence interval, 0.98 to 1.40). CONCLUSIONS: In patients with treated hypertension, a higher ambulatory systolic or diastolic blood pressure predicts cardiovascular events even after adjustment for classic risk factors including office measurements of blood pressure.

Prognostic significance of ambulatory blood pressure in hypertensive patients with history of cardiovascular disease.

OBJECTIVE: To assess the prognostic significance of nighttime and daytime blood pressure (BP), their ratio and the nighttime dipping pattern for mortality and recurrent cardiovascular (CV) events in patients with CV disease at baseline. BACKGROUND: The prognostic value of ambulatory BP has not been reported in hypertensive patients with a history of CV disease. METHODS: We performed a meta-analysis on individual data of 302 patients with hypertension and CV disease from three prospective studies performed in Europe. RESULTS: Age of the patients averaged 69+/-9 years; 50% were men and 62% were under antihypertensive treatment at the time of ambulatory BP monitoring. Office, daytime and nighttime BP averaged 161+/-20/86+/-12, 144+/-16/83+/-11 and 132+/-18/72+/-12 mmHg. Total follow-up time amounted to 2049 patient--years. Multivariable Cox regression analysis revealed that nighttime BP, but not daytime BP significantly predicted CV mortality (P< or =0.05) and major CV events (P< or =0.01) after adjustment for office BP and other confounders. When both nighttime and daytime BP were entered into the models, the predictive power of nighttime BP remained significant (P< or =0.05); daytime BP did not add prognostic precision to nighttime BP. The systolic nightday BP ratio predicted all outcomes, and outcome was significantly worse in reverse dippers and nondippers than in dippers, both before and after adjustment for 24-h BP (P< or =0.05). CONCLUSION: Nighttime BP is the better predictor of death and recurrent CV events in hypertensive patients with a history of CV disease. The night-day BP ratio and the dipping pattern significantly predict outcome, even after adjustment for 24-h BP.

Daytime and nighttime blood pressure as predictors of death and cause-specific cardiovascular events in hypertension.

Our aim was to assess the prognostic significance of nighttime and daytime ambulatory blood pressure and their ratio for mortality and cause-specific cardiovascular events in hypertensive patients without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from 4 prospective studies performed in Europe. Age of the subjects averaged 61+/-13 years, 45% were men, 13.7% smoked, 8.4% had diabetes, and 61% were under antihypertensive treatment at the time of ambulatory blood pressure monitoring. Office, daytime, and nighttime blood pressure averaged 159+/-20/91+/-12, 143+/-17/87+/-12, and 130+/-18/75+/-12 mm Hg. Total follow-up amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the hazard ratios associated with 1 standard deviation higher blood pressure. Daytime and nighttime systolic blood pressure predicted all-cause and cardiovascular mortality, coronary heart disease, and stroke, independently from office blood pressure and confounding variables. When these blood pressures were entered simultaneously into the models, nighttime blood pressure predicted all outcomes, whereas daytime blood pressure did not add prognostic precision to nighttime pressure. Appropriate interaction terms indicated that the results were similar in men and women, in younger and older patients, and in treated and untreated patients The systolic night-day blood pressure ratio predicted all outcomes, which only persisted for all-cause mortality after adjustment for 24-hour blood pressure. In conclusion, nighttime blood pressure is in general a better predictor of outcome than daytime pressure in hypertensive patients, and the night-day blood pressure ratio predicts mortality, even after adjustment for 24-hour blood pressure.