Elevated serum uric acid levels following heart transplantation predict all-cause and cardiac mortality

AIMS

We evaluated the relationship between elevated serum uric acid (SUA) and mortality as well as cardiac allograft vasculopathy (CAV) among 184 heart transplant (HTx) recipients. We also measured inflammatory, neurohormonal, and oxidative stress markers to explore pathophysiological mechanisms.

METHODS AND RESULTS

There were 28 (15%) deaths, patients with SUA > or = 502 micromol/L (upper quartile) at 1 year post-HTx had an increased risk of total mortality (adjusted HR 2.21, P = 0.03) and cardiac mortality (adjusted HR 4.38, P = 0.03). Elevated SUA was a significant risk factor for development of moderate/severe angiographic CAV (adjusted HR 4.79, P = 0.01). A smaller decline in SUA (<97 micromol/L) during the first year post-HTx was also associated with an increased risk of mortality (P = 0.02). Patients with elevated SUA had significantly higher levels of high-sensitivity C-reactive protein (P = 0.008) and N-terminal probrain natriuretic peptide (P = 0.022), but there was no significant difference in oxidative stress parameters.

CONCLUSION

Elevated SUA at 1 year post-HTx, or a modest rather than a marked decline in SUA levels during the first year post-HTx, is associated with an increased risk of mortality. Although the pathophysiological mechanism is unclear, our data indicate a potential relationship between SUA and inflammation which should be explored further.

The prognostic importance of modifiable risk factors after heart transplantation

BACKGROUND

It is well established that the treatment of modifiable risk factors can reduce cardiovascular mortality in the general population. However, there is limited data evaluating the importance of modifiable risk factors for survival following heart transplantation (HTx). Hence, we evaluated the prognostic importance of smoking, obesity, hyperglycemia and hyperlipidemia at 1 year after HTx for all-cause and cardiac mortality.

METHODS

We evaluated 381 patients attending their first annual visit post-HTx. Data regarding modifiable risk factors was collected together with other clinical variables. Median follow-up time was 7.4 years.

RESULTS

In total, there were 122 (32%) deaths and smoking and elevated total cholesterol were independent risk factors for all-cause mortality (adjusted HR 1.6 [P = .02] and 1.8 [P = .003], respectively). A significantly higher incidence of cardiac death was noted amongst smokers and patients with elevated total cholesterol. Elevated body mass index and hemoglobin A(1c) did not affect prognosis and elevated total cholesterol was not a risk factor once statin therapy commenced at the time of HTx was instituted as protocol.

CONCLUSIONS

Smoking is a risk factor for all-cause and cardiac mortality, but elevated total cholesterol is a risk factor only in the absence of statin therapy being commenced at the time of HTx.

Prognostic Importance of Renal Function 1 Year After Heart Transplantation for All-Cause and Cardiac Mortality and Development of Allograft Vasculopathy

BACKGROUND

Impaired renal function is associated with increased mortality among heart failure patients. Although a significant proportion of heart transplant (HTx) recipients have reduced renal function at 1 year post-HTx, no previous study has evaluated the associated risk for both all-cause and cardiac mortality. Hence, we assessed the relationship between glomerular filtration rate (GFR) at 1 year post-HTx and all-cause and cardiac mortality and development of cardiac allograft vasculopathy (CAV).

METHODS

We evaluated 381 patients with a minimum survival of 1 year post-HTx and the Modification of Diet in Renal Disease Study formula was used to calculate estimated GFR. Mortality and angiographic CAV were defined as separate endpoints, and median follow-up was 7.4 and 4.0 years, respectively.

RESULTS

During the follow-up period, 122 patients died and 154 patients developed CAV. Reduced GFR pre-HTx was not a risk factor for either endpoint. Overall, 193 (51%) patients had GFR <60 ml/min/1.73 m at one year post-HTx and this was an independent predictor of all-cause mortality with an adjusted hazard ratio of 1.7 (P=0.01) for a GFR between 30-60 and 3.2 (P=0.006) for GFR <30 ml/min/1.73 m. GFR <60 ml/min/1.73 m at 1 year post-HTx was also associated with a higher risk of cardiac mortality (HR=1.9; P=0.04) but did not predict the development of CAV.

CONCLUSIONS

Renal impairment is evident in a majority of HTx recipients at 1 year post-HTx. It is an important risk factor for both all-cause and cardiac mortality but does not predict the development of angiographic CAV.