The renal-cardiac connection in subjects with preserved ejection fraction: a population based study

Chronic kidney disease (CKD) is prevalent and is associated with increased cardiovascular morbidity and mortality. The interaction between diastolic dysfunction (DD) and CKD in subjects with preserved systolic function is not well defined. This study sought to determine the association between renal function and DD in subjects with preserved ejection fraction.

Through the Rochester Epidemiology Project, subjects who underwent echocardiography over 2 years with EF ≥50% were identified and the clinical data were obtained. Glomerular filtration rate (GFR) was estimated using the modification of diet in renal disease equation. Linear regression was used to test for association of GFR and DD. DD was defined as follows: Grade 2 or pseudonormal pattern (0.75 < E/A ≤ 1.5, E/e' ≥ 10, DT > 140 ms, ΔE/A ≥ 0.5, and PV S < D) or Grade 3+ or restrictive pattern (E/A > 1.5, E/e' ≥ 10, DT < 140 ms, and PV S < D). Cox regression was used to assess correlation of GFR and DD with time-to-event outcomes. A total of 2056 patients were identified. There was significant correlation between worsening GFR and degree of DD assessed by echo Doppler E/e' ratio (P = 0.005), left ventricular mass index (P = 0.004), and right ventricular systolic pressure (P = 0.01). Worsening GFR was associated with increased mortality, development of heart failure, and hospitalization (P < 0.001). Within each GFR group, abnormal DD was associated with a higher risk of the clinical outcomes. No interaction between GFR and DD was noted, suggesting an increased risk of events associated with abnormal DD across ranges of GFR.

Worsening GFR was associated with a greater degree of diastolic dysfunction and adverse clinical outcomes. Within each GFR group, the presence of DD was associated with increased morbidity and mortality. Further studies are warranted to determine if improving DD in patients with CKD will benefit clinical outcomes.