Heat shock protein 70 in patients with chronic heart failure: relation to disease severity and survival

Background: Heat shock protein 70 (Hsp70) is essential for cellular recovery, survival and maintenance of cellular function. Research into the possible use of Hsp70 as a cytoprotective therapeutic agent is ongoing. Chronic heart failure (CHF) is a state associated with systemic inflammation, particularly in patients with cardiac cachexia. We hypothesised that circulating Hsp70 levels are elevated in patients with CHF, more so in cachechtic patients, and that Hsp70 levels would relate to mortality. Methods and results: We studied 107 patients (28 female, age 67 +/- 1 years, NYHA class 2.6 +/- 0.6 and LVEF 29 +/- 1%, mean +/- SEM) and 21 controls. Cardiac cachexia was present in 32 patients. Hsp70 was detectable in 41% of CHF patients and in only 10% of controls. Overall serum levels were significantly higher in CHF patients vs. controls (7.13 +/- 1.34 vs. 0.38 +/- 0.26 ng/ml, p = 0.004). Hsp70 levels were also higher in patients with advanced CHF according to NYHA class or the presence of cachexia (all p < 0.05). There was no relation between Hsp70 and left ventricular ejection fraction, maximal oxygen consumption and several inflammatory cytokines (all p > 0.05). During a median follow-up of 208 days (range 4 - 2745 days) 38 patients died. Cox proportional hazards analysis showed that increased Hsp70 did not predict survival (p = 0.17). Conclusion: Hsp70 levels are elevated in CHF patients, particularly in those with cardiac cachexia and Hsp70 relates to disease severity but not to survival. The significance of the relationship of Hsp70 expression and morbidity in CHF needs further evaluation. (C) 2003 Elsevier Ireland Ltd. All rights reserved.