RESUMO
Objective: Prolonged QT interval predisposes to ventricular arrhythmias and sudden cardiac death. However, the association between QT interval and mortality by the level of pre-existing kidney function has not been investigated. Methods: We followed 6565 participants from the National Health and Nutrition Examination Survey III for a median of 13.3 years. Sample divided according to corrected QT (QTc) interval was as follows: normal (QTc <450 ms for men and <460 ms for women) or prolonged. It was further categorised as follows: (1) no chronic kidney disease (CKD), that is, albumin to creatinine ratio (ACR) <30 mg/g and estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2; (2) CKD by eGFR only (eGFR <60 mL/min/1.73 m2, ACR <30 mg/g); (3) CKD by ACR only (ACR >30 mg/g, eGFR >60 mL/min/1.73 m2) and (4) CKD by both. Cox proportional hazards models were used. Results: CKD group had prolonged QTc than those without CKD (20.5%vs12.9%, p<0.0001). Both prolonged QTc and CKD are independently associated with increased risk of mortality. When combined, risk of mortality is higher in those with CKD by eGFR with prolonged QTc than normal QTc (HR 2.6 (1.7-3.9) and 3.1 (1.7-5.4) vs 1.4 (1.1-1.7) and 1.7 (1.3-2.1) for all-cause and CV mortality). There is no significant difference in risk in those with CKD by ACR when QTc is prolonged. There is significant improvement in risk prediction for all-cause and CV mortality when QTc is added to CKD beyond established CV risk factors (net reclassification index p<0.00001). Conclusion: A screening ECG in those with CKD may help in finer risk stratification and may be considered.
RESUMO
BACKGROUND AND AIM: To investigate whether pre-existing diabetes modifies racial disparities in colorectal cancer (CRC) survival. METHODS: We analyzed prospective data from 16 977 patients (age ≥ 67 years) with CRC from the Surveillance Epidemiology and End Results (SEER)-Medicare database. SEER registries included data on demographics, tumor characteristics, and treatment. Medicare claims were used to define pre-existing diabetes and comorbid conditions. Mortality was confirmed in both sources. RESULTS: At baseline, 1332 (8%) were African Americans and 26% had diabetes (39% in blacks; 25% in whites). From 2000 to 2005, more than half of the participants died (n = 8782, 52%). This included 820 (62%) deaths (23.8 per 100 person-years) among blacks, and 7962 (51%) deaths (16.6 per 100 person-years) among whites. Among older adults with diabetes, blacks had significantly higher risk of all-cause and CRC mortality after adjustments for demographic characteristics (hazard ratio [HR], 95% confidence interval [CI]: 1.21 [1.08-1.37] and 1.21 [1.03-1.42]), respectively, but these associations attenuated to null after additional adjustments for cancer stage and grade. Among adults without diabetes, the risk of all-cause mortality (HR [95% CI]: 1.14 [1.04-1.25]) and CRC mortality (HR [95% CI]: 1.21 [1.08-1.36]) remained higher in blacks than whites in fully adjusted models that included demographic variables, cancer stage, grade, treatments, and comorbidities. CONCLUSIONS: Among older adults with CRC, diabetes is an effect modifier on the relationship between race and mortality. Racial disparities in survival were explained by demographics, cancer stage, and grade in patients with diabetes.
