Chronic Kidney Disease as a Risk Factor for Heart Failure With Preserved Ejection Fraction: A Focus on Microcirculatory Factors and Therapeutic Targets

Current guidelines identify people with chronic kidney disease (CKD) as being at high risk for cardiovascular and all-cause mortality. Because as many as 19 million Americans may have CKD, a comprehensive summary of this risk would be potentially useful for planning public health policy. A systematic review of the association between non-dialysis-dependent CKD and the risk for all-cause and cardiovascular mortality was conducted. Patient- and study-related characteristics that influenced the magnitude of these associations also were investigated. MEDLINE and EMBASE databases were searched, and reference lists through December 2004 were consulted. Authors of 10 primary studies provided additional data. Cohort studies or cohort analyses of randomized, controlled trials that compared mortality between those with and without chronically reduced kidney function were included. Studies were excluded from review when participants were followed for < 1 yr or had ESRD. Two reviewers independently extracted data on study setting, quality, participant and renal function characteristics, and outcomes. Thirty-nine studies that followed a total of 1,371,990 participants were reviewed. The unadjusted relative risk for mortality in participants with reduced kidney function compared with those without ranged from 0.94 to 5.0 and was significantly more than 1.0 in 93% of cohorts. Among the 16 studies that provided suitable data, the absolute risk for death increased exponentially with decreasing renal function. Fourteen cohorts described the risk for mortality from reduced kidney function, after adjustment for other established risk factors. Although adjusted relative hazards were consistently lower than unadjusted relative risks (median reduction 17%), they remained significantly more than 1.0 in 71% of cohorts. This review supports current guidelines that identify individuals with CKD as being at high risk for cardiovascular mortality. Determining which interventions best offset this risk remains a health priority.

The importance of heart failure with preserved ejection fraction is increasingly recognized. We conducted a study to evaluate the epidemiologic features and outcomes of patients with heart failure with preserved ejection fraction and to compare the findings with those from patients who had heart failure with reduced ejection fraction. From April 1, 1999, through March 31, 2001, we studied 2802 patients admitted to 103 hospitals in the province of Ontario, Canada, with a discharge diagnosis of heart failure whose ejection fraction had also been assessed. The patients were categorized in three groups: those with an ejection fraction of less than 40 percent (heart failure with reduced ejection fraction), those with an ejection fraction of 40 to 50 percent (heart failure with borderline ejection fraction), and those with an ejection fraction of more than 50 percent (heart failure with preserved ejection fraction). Two groups were studied in detail: those with an ejection fraction of less than 40 percent and those with an ejection fraction of more than 50 percent. The main outcome measures were death within one year and readmission to the hospital for heart failure. Thirty-one percent of the patients had an ejection fraction of more than 50 percent. Patients with heart failure with preserved ejection fraction were more likely to be older and female and to have a history of hypertension and atrial fibrillation. The presenting history and clinical examination findings were similar for the two groups. The unadjusted mortality rates for patients with an ejection fraction of more than 50 percent were not significantly different from those for patients with an ejection fraction of less than 40 percent at 30 days (5 percent vs. 7 percent, P=0.08) and at 1 year (22 percent vs. 26 percent, P=0.07); the adjusted one-year mortality rates were also not significantly different in the two groups (hazard ratio, 1.13; 95 percent confidence interval, 0.94 to 1.36; P=0.18). The rates of readmission for heart failure and of in-hospital complications did not differ between the two groups. Among patients presenting with new-onset heart failure, a substantial proportion had an ejection fraction of more than 50 percent. The survival of patients with heart failure with preserved ejection fraction was similar to that of patients with reduced ejection fraction. Copyright 2006 Massachusetts Medical Society.

Approximately half of patients with overt congestive heart failure (CHF) have diastolic dysfunction without reduced ejection fraction (EF). Yet, the prevalence of diastolic dysfunction and its relation to systolic dysfunction and CHF in the community remain undefined. To determine the prevalence of CHF and preclinical diastolic dysfunction and systolic dysfunction in the community and determine if diastolic dysfunction is predictive of all-cause mortality. Cross-sectional survey of 2042 randomly selected residents of Olmsted County, Minnesota, aged 45 years or older from June 1997 through September 2000. Doppler echocardiographic assessment of systolic and diastolic function. Presence of CHF diagnosis by review of medical records with designation as validated CHF if Framingham criteria are satisfied. Subjects without a CHF diagnosis but with diastolic or systolic dysfunction were considered as having either preclinical diastolic or preclinical systolic dysfunction. The prevalence of validated CHF was 2.2% (95% confidence interval [CI], 1.6%-2.8%) with 44% having an EF higher than 50%. Overall, 20.8% (95% CI, 19.0%-22.7%) of the population had mild diastolic dysfunction, 6.6% (95% CI, 5.5%-7.8%) had moderate diastolic dysfunction, and 0.7% (95% CI, 0.3%-1.1%) had severe diastolic dysfunction with 5.6% (95% CI, 4.5%-6.7%) of the population having moderate or severe diastolic dysfunction with normal EF. The prevalence of any systolic dysfunction (EF < or =50%) was 6.0% (95% CI, 5.0%-7.1%) with moderate or severe systolic dysfunction (EF < or =40%) being present in 2.0% (95% CI, 1.4%-2.5%). CHF was much more common among those with systolic or diastolic dysfunction than in those with normal ventricular function. However, even among those with moderate or severe diastolic or systolic dysfunction, less than half had recognized CHF. In multivariate analysis, controlling for age, sex, and EF, mild diastolic dysfunction (hazard ratio, 8.31 [95% CI, 3.00-23.1], P<.001) and moderate or severe diastolic dysfunction (hazard ratio, 10.17 [95% CI, 3.28-31.0], P<.001) were predictive of all-cause mortality. In the community, systolic dysfunction is frequently present in individuals without recognized CHF. Furthermore, diastolic dysfunction as rigorously defined by comprehensive Doppler techniques is common, often not accompanied by recognized CHF, and associated with marked increases in all-cause mortality.