Diastolic heart failure versus diastolic dysfunction: difference in renal function.

BACKGROUND: Despite the common finding of diastolic dysfunction with a preserved ejection fraction on routine echocardiography in elderly patients, it is unknown why some patients with isolated diastolic dysfunction are asymptomatic whereas others develop diastolic heart failure (ie, signs and symptoms of congestive heart failure). HYPOTHESIS: We hypothesized that renal insufficiency is more common in those patients with diastolic heart failure than those with diastolic dysfunction; it is intrinsic renal insufficiency that determines whether diastolic dysfunction becomes symptomatic.
METHODS: We reviewed 686 consecutive transthoracic echocardiograms (TTEs). Patient age, race, weight, and cardiovascular risk factors (hypertension, diabetes, and coronary artery disease) were recorded. We used the Framingham Criteria for Congestive Heart Failure to determine the presence of diastolic heart failure by symptoms, exam findings, and radiological studies. Average creatinine clearance (CrCl), calculated by both total body weight and lean body mass, and estimated glomerular filtration rate (eGFR) were calculated for each group.
RESULTS: Of the 686 TTEs reviewed, 18 patients fulfilled the criteria for diastolic heart failure and 118 patients had asymptomatic diastolic dysfunction. There was no difference in age, race, or gender nor was there any difference in the echocardiographic variables of diastolic function or left ventricular hypertrophy between groups. Multiple regression analysis showed only lower CrCl (44 ± 36 mL/min vs 76 ± 42 mL/min, total body weight, P = 0.0015; and 31 ± 24 mL/min vs 51 ± 27 mL/min, lean body mass, P = 0.0012) and eGFR (44 ± 33 mL/min/M² vs 69 ± 28 mL/min/M², P = 0.0003) were associated with diastolic heart failure. There was no significant difference in the presence of hypertension, diabetes, and coronary artery disease between groups.
CONCLUSIONS: The results of this study support the hypothesis that patients with normal left ventricular ejection fractions but diastolic dysfunction develop congestive heart failure because of underlying renal insufficiency. A larger, prospective study is needed to confirm this hypothesis.