Background: Both atrial cardiopathy and impaired renal function are independently associated with increased mortality, but their interrelationship and combined impact remain uncertain. Methods: We analyzed 6573 participants from NHANES-III (mean age 57 years; 50.5% women; 74.6% White) with available electrocardiograms (ECGs). Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Atrial cardiopathy was defined by any of the following ECG markers: abnormal P-wave axis (75°), deep terminal negativity in lead V1 (>100 µV), or prolonged P-wave duration in lead II (>120 ms). Participants with eGFR <15 mL/min/1.73 m² or major ECG abnormalities were excluded. Logistic regression assessed the association between impaired renal function (eGFR < 45 vs. ≥45 mL/min/1.73 m²) and atrial cardiopathy. Cox models evaluated independent and joint associations of impaired renal function and atrial cardiopathy with all-cause mortality. Results: About 47.9% (n = 3151) had atrial cardiopathy at baseline, of whom 161 (4.7%) had impaired renal function. Impaired renal function was associated with higher odds of atrial cardiopathy (OR 1.44; 95% CI 1.16–1.78). Over a median follow-up of 18.1 years, 3076 deaths occurred. Compared with participants without either condition, those with both had the highest mortality risk (HR 1.68; 95% CI 1.46–1.94), exceeding risks from atrial cardiopathy alone (HR 1.10; 95% CI 1.02–1.18) or impaired renal function alone (HR 1.42; 95% CI 1.18–1.70; p = 0.011 for interaction). Conclusions: Impaired renal function is associated with a greater prevalence of atrial cardiopathy. Their coexistence exerts a synergistic effect, substantially amplifying mortality risk beyond either condition alone.

Background: The combined impact of impaired kidney function and subclinical myocardial injury (SCMI) on cardiovascular (CV) mortality has not been well studied. We aimed to evaluate their individual and joint associations with cardiovascular mortality. Methods: We analyzed data from 6057 participants (mean age 57.0 ± 13.0 years) in the U.S. Third National Health and Nutrition Examination Survey. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Electrocardiographic SCMI was defined as a cardiac infarction/injury score ≥ 10. CV mortality was determined from the National Death Index. Multivariable logistic regression assessed baseline cross-sectional associations between eGFR and SCMI. Cox proportional hazards models were used to examine the individual and combined associations of eGFR and SCMI with CV mortality. Results: At baseline, 1297 participants (21.4%) had SCMI. In multivariable logistic regression analysis, eGFR < 45 mL/min/1.73 m² (vs. ≥45) was not associated with SCMI (OR [95% CI]: 1.10 [0.84–1.45]). Over a median follow-up of 18.4 years, 690 CV deaths occurred. In separate Cox models, both SCMI (vs. no SCMI) and eGFR < 45 (vs. ≥45) were associated with increased CV mortality risk (HR [95% CI]: 1.36 [1.16–1.60] and 1.56 [1.24–1.99], respectively). Compared with participants with eGFR ≥ 45 and no SCMI, those with both eGFR < 45 and SCMI had the highest CV mortality risk (HR [95% CI]: 2.36 [1.65–3.36]), followed by eGFR < 45 alone (1.47 [1.09–1.96]) and SCMI alone (1.33 [1.11–1.58]). Conclusions: Both reduced eGFR and SCMI were independently associated with CV mortality. Their coexistence showed the highest risk, but without statistical significance compared with each alone, possibly reflecting limited power and distinct mechanisms.

Background: The combined impact of impaired kidney function and subclinical myocardial injury (SCMI) on cardiovascular (CV) mortality has not been well studied. Methods: We analyzed data from 6,057 participants (mean age 57.0 ± 13.0 years) in the U.S. Third National Health and Nutrition Examination Survey. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Electrocardiographic SCMI was defined as a cardiac infarction/injury score ≥10. CV mortality was determined from the National Death Index. Multivariable logistic regression assessed baseline cross-sectional associations between eGFR and SCMI. Cox proportional hazards models were used to examine the individual and combined associations of eGFR and SCMI with CV mortality. Results: At baseline, 1,297 participants (21.4%) had SCMI. In multivariable logistic regression analysis, eGFR <45 mL/min/1.73 m² (vs. ≥45) was not associated with SCMI (OR [95% CI]:1.10[0.84–1.45]). Over a median follow-up of 18.4 years, 690 CV deaths occurred. In separate Cox models, both SCMI (vs. no SCMI) and eGFR <45 (vs. ≥45) were associated with increased CV mortality risk (HR [95% CI]: 1.36[1.16–1.60] and 1.56 [1.24–1.99], respectively). Compared with participants with eGFR ≥45 and no SCMI, those with both eGFR <45 and SCMI had the highest CV mortality risk (HR[95% CI]:2.36[1.65–3.36]), followed by eGFR <45 alone (1.47[1.09–1.96]) and SCMI alone (1.33[1.11–1.58]). Conclusions: Both reduced eGFR and SCMI are independently associated with increased CV mortality. Their combined effect appears synergistic, possibly reflecting distinct underlying mechanisms, as suggested by their lack of significant association with each other at baseline.

Background: Both atrial cardiopathy and impaired renal function are independently associated with increased mortality, but their interrelationship and combined impact remain uncertain. Methods: We analyzed 6,573 participants from NHANES-III (mean age 57 years; 50.5% women; 74.6% White) with available electrocardiograms (ECGs). Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Atrial cardiopathy was defined by any of the following ECG markers: abnormal P-wave axis (< 0° or >75°), deep terminal negativity in lead V1 (>100 µV), or prolonged P-wave duration in lead II (>120 ms). Participants with eGFR < 15 mL/min/1.73 m² or major ECG abnormalities were excluded. Logistic regression assessed the association between impaired renal function (eGFR < 45 vs ≥45 mL/min/1.73 m²) and atrial cardiopathy. Cox models evaluated independent and joint associations of impaired renal function and atrial cardiopathy with all-cause mortality. Results: About 47.9% (n=3,151) had atrial cardiopathy at baseline, of whom 161(4.7%) had impaired renal function. Impaired renal function was associated with higher odds of atrial cardiopathy (OR 1.44; 95% CI 1.16–1.78). Over a median follow-up of 18.1 years, 3,076 deaths occurred. Compared with participants without either condition, those with both had the highest mortality risk (HR 1.68; 95% CI 1.46–1.94), exceeding risks from atrial cardiopathy alone (HR 1.10; 95% CI 1.02–1.18) or impaired renal function alone (HR 1.42; 95% CI 1.18–1.70; p=0.011 for interaction). Conclusions: Impaired renal function is associated with a greater prevalence of atrial cardiopathy. Their coexistence exerts a synergistic effect, substantially amplifying mortality risk beyond either condition alone.