Hemodialysis-induced cardiac injury: determinants and associated outcomes

Abstract

Background and objectives: Hemodialysis (HD)-induced myocardial stunning driven by ischemia is a recognized complication of HD, which can be ameliorated by HD techniques that improve hemodynamics. In nondialysis patients, repeated ischemia leads to chronic reduction in left ventricular (LV) function. HD may initiate and drive the same process. In this study, we examined the prevalence and associations of HD-induced repetitive myocardial injury and long-term effects on LV function and patient outcomes.

Design, setting, participants, & measurements: Seventy prevalent HD patients were assessed for evidence of subclinical myocardial injury at baseline using serial echocardiography and followed up after 12 mo. Intradialytic blood pressure, hematologic and biochemical samples, and patient demographics were also collected at both time points.

Results: Sixty-four percent of patients had significant myocardial stunning during HD. Age, ultrafiltration volumes, intradialytic hypotension, and cardiac troponin-T (cTnT) levels were independent determinants associated with its presence. Myocardial stunning was associated with increased relative mortality at 12 mo (P = 0.019). Cox regression analysis showed increased hazard of death in patients with myocardial stunning and elevated cTnT than in patients with elevated cTnT alone (P < 0.02). Patients with myocardial stunning who survived 12 mo had significantly lower LV ejection fractions at rest and on HD (P < 0.001).

Conclusions: HD-induced myocardial stunning is common, and may contribute to the development of heart failure and increased mortality in HD patients. Enhanced understanding of dialysis-induced cardiac injury may provide novel therapeutic targets to reduce currently excessive rates of cardiovascular morbidity and mortality.

Figure 1.

Reduction in systolic BP (SBP) during hemodialysis (HD) in patients with and without HD-induced regional wall motion abnormalities (RWMAs). At baseline there was a significant reduction in SBP during HD in patients with HD-induced RWMAs (P < 0.0001); however, patients without such RWMAs did not have a significant reduction in their SBP (P = 0.16).

Figure 2.

The association of hemodialysis-induced RWMAs with mortality and outcome. (A) The development of HD-induced RWMAs was associated with increased relative mortality at 12 mo (P = 0.019) and (B) reduced survival to a composite end point of mortality and time to first cardiovascular event (P = 0.017).