Correlation of Cystatin-C and radionuclidic measurement method of glomerular filtration rate in patients with lung cancer receiving cisplatin treatment.

OBJECTIVE: Cisplatin is a chemotherapeutic agent which affects renal functions adversely. The best indicator of renal functions is glomerular filtration rate (GFR) measurement. Cystatin-C appears to be a good alternative to existing methods of measuring GFR. However, it is controversial whether Cystatin-C demonstrates GFR correctly for patients receiving chemotherapy. This study aimed to investigate the correlation between GFR values calculated by Cystatin-C based formulas, radionuclidic method (multiple blood sampling) and blood Cystatin-C values in patients with lung cancer, receiving cisplatin treatment in both pre-treatment and post-treatment periods. MATERIALS AND METHODS: Thirty-six patients with lung cancer who were going to receive cisplatin treatment were included in this study. However, the evaluation was performed with 20 patients since 16 of them could not complete the treatment. Blood Cystatin-C values, GFR values calculated via Cystatin-C based formulas, and radionuclidic method were investigated before and after the cisplatin treatment. RESULTS: After treatment significant decreases were detected in GFR values, obtained via radionuclidic measuring method. However, there was no significant difference in Cystatin-C values between pre-treatment and post-treatment periods. Also GFR values obtained by Cystatin-C based formulas were not significantly different in pre-treatment and post-treatment periods. There were meaningful correlations between radionuclidic method and Cystatin-C values and Cystatin-C based formulas before treatment. However, all correlations disappeared after the treatment. CONCLUSION: GFR values, calculated by Cystatin-C may not be reliable in following renal functions in patients receiving chemotherapy. When reliable monitoring of the renal functions is necessary radionuclidic method may be preferred in these patients.

Reduced heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT.

OBJECTIVE: A mild decrease in blood pressure and increase in heart rate (HR) are considered normal hemodynamic responses to dipyridamole. In this study, we tried to investigate HR response to dipyridamole and its predictors in patients undergoing gated myocardial perfusion single photon emission computed tomography (SPECT). METHODS: 201 consecutive patients undergoing dipyridamole stress Tc99m-MIBI or Tl-201 gated myocardial perfusion SPECT were prospectively enrolled. Dipyridamole was infused over 4 min and radiopharmaceutical was injected 3 min after the end of infusion. A reduced heart rate response to dipyridamole considered if the HR ratio (peak HR/rest HR) was 1.20 or less. Stress (sLVEF), rest (rLVEF) left ventricular ejection fractions, stress and rest motion (SMS, RMS) and thickening scores (STS, RTS) were derived automatically by QGS. Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion were calculated. Patients were grouped according to HR response and groups were compared. A logistic regression analysis was used to determine independent predictors of reduced HR response. RESULTS: Reduced HR response was found in 78 % of patients. Patients with abnormal HR response were more frequently had a history of diabetes mellitus, chronic renal failure, and had lower high-density lipoprotein (HDL) levels. Peak HR, SSS, SRS, sLVEF and rLVEF were lower; rest HR, RTS, and the number of patients with ≤ 45 % sLVEF and rLVEF were higher in reduced HR response group (all p < 0.05). There was no difference between groups by means of gender, rest and peak systolic or diastolic tension, SDS, SMS, STS, RMS, history of hypertension, peripheral arterial disease, metabolic syndrome, coronary interventions, digoxin, calcium channel blocker or beta blocker usage. Multivariable logistic regression analysis demonstrated that the independent predictors of reduced HR response were HDL, rest HR and SSS. When HDL was removed from the model, chronic renal failure also emerged as an independent predictor. CONCLUSION: Reduced HR response to dipyridamole is associated with ventricular dysfunction, cardiac autonomic neuropathy. Low HDL levels also seem to be related with reduced HR response.