Reduced Estimated GFR and Cardiac Remodeling: A Population-Based Autopsy Study

Abstract

Rationale & Objective: Evidence suggests that cardiac remodeling, including left ventricular hypertrophy and myocardial fibrosis, develops with progression of kidney disease. Few studies have examined cardiac pathology across a range of estimated glomerular filtration rates (eGFRs), which was the objective of this investigation. Study Design: Population-based cross-sectional study of deceased patients undergoing autopsy. Setting & Participants: 334 of 694 consecutive deceased patients undergoing autopsy with available cardiac tissue, with a prior health examination within 6 years and without a prior diagnosis of heart disease. Exposure: eGFR. Outcomes: The thickness of the left ventricular wall, sizes of cardiac cells, and percentages of fibrosis, estimated from pathology examination of autopsy samples. Analytical Approach: Generalized estimating equations. Results: Lower eGFRs were associated with greater left ventricular wall thickness. Deceased patients with eGFRs ≥ 60, 45 to 59, 30 to 44, and <30 mL/min/1.73 m2 had left ventricular wall thicknesses of 9.1, 9.5, 9.8, and 10.3 mm, respectively (P for trend < 0.05). Lower eGFRs were also significantly associated with greater mean values of cardiac cell size in the left ventricular wall after adjusting for confounders: 15.3, 16.1, 16.4, and 17.4 μm for eGFRs ≥ 60, 45 to 59, 30 to 44, and <30 mL/min/1.73 m2 (P for trend < 0.01). Patients with lower eGFRs had significantly higher multivariable-adjusted geometric mean values for fibrosis percentage in the left ventricular wall: 3.22%, 4.33%, 3.83%, and 6.14% for eGFRs ≥ 60, 45 to 59, 30 to 44, and <30 mL/min/1.73 m2 (P for trend < 0.001). The negative association of eGFR with multivariable-adjusted mean values of cardiac cell width was stronger among patients with than those without anemia. Limitations: Cross-sectional study with a high proportion of elderly patients, no available information for severity or duration of hypertension and other cardiovascular risk factors, no information for medication use. Conclusions: These findings suggest that reduced eGFR is associated with cardiac hypertrophy and fibrosis of the left ventricle, cardiac cell enlargement, and cardiac fibrosis.