Table 2

Overall and joint association of QTc and CKD with all-cause and cardiovascular mortality

All-cause mortalityCardiovascular mortality
Normal QTcProlonged QTcOverallNormal QTcProlonged QTcOverall
Model 1Model 1
No CKDReference1.7 (1.4–2.1)ReferenceNo CKDReference1.6 (1.2–2.1)Reference
CKD by eGFR only1.5 (1.2–1.8)2.6 (1.7–3.9)1.5 (1.3–1.8)CKD by eGFR only1.8 (1.4–2.2)3.1 (1.7–5.5)1.8 (1.4–2.2)
CKD by ACR only2.0 (1.7–2.3)2.0 (1.4–3.0)1.9 (1.7–2.2)CKD by ACR only2.4 (1.7–3.3)2.3 (1.4–3.9)2.1 (1.6–2.8)
OverallReference1.5 (1.3–1.8)OverallReference1.4 (1.1–1.8)
Model 2Model 2
No CKDReference1.6 (1.3–1.9)ReferenceNo CKDReference1.5 (1.1–1.9)Reference
CKD by eGFR only1.4 (1.1–1.7)2.6 (1.7–3.9)1.4 (1.2–1.7)CKD by eGFR only1.7 (1.3–2.1)3.1 (1.7–5.4)1.7 (1.3–2.1)
CKD by ACR only1.9 (1.6–2.2)1.8 (1.2–2.6)1.8 (1.5–2.0)CKD by ACR only2.2 (1.5–3.1)1.9 (1.2–3.2)2.0 (1.5–2.6)
OverallReference1.4 (1.2–1.7)OverallReference1.3 (1.0–1.7)
  • Model 1 adjusted for age, race, gender, income and educational status.

  • Model 2 further adjusted for diabetes, hypertension, history of cardiovascular disease, smoking, alcohol, total cholesterol, serum potassium, serum calcium, QT-prolonging medications and beta-blockers use.

  • Interaction p value from the fully adjusted model: prolonged QTc × CKD by eGFR=not significant, QT × CKD by ACR=not significant for all-cause and cardiovascular mortality.

  • Net reclassification index from the fully adjusted model adding QTc to CKD. NRI was 0.166, p<0.00001 for all-cause mortality and NRI 0.162, p<0.00001 for CV mortality.

  • ACR, albumin to creatinine ratio; CKD, chronic kidney disease; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; NRI, net reclassification index; QTc, corrected QT.