Incremental prognostic information from kidney function in patients with new onset coronary heart disease

Area of Science:

• Cardiology
• Nephrology
• Clinical Epidemiology

Background:

• Prognostic factors are often assessed by statistical significance, not clinical utility.
• Risk reclassification quantifies a new marker's added prognostic information.
• The prognostic value of estimated glomerular filtration rate (eGFR) in coronary heart disease (CHD) is unclear.

Purpose of the Study:

• To evaluate the clinical utility of eGFR in predicting mortality risk in patients with incident coronary heart disease.
• To determine if eGFR improves existing prognostic models for CHD.

Main Methods:

• A cohort of 31,533 patients with newly diagnosed CHD was studied.
• A 2-year mortality risk model was developed and then augmented with eGFR.
• Model performance was assessed using C-index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Main Results:

• Nearly half of the patients had reduced eGFR (<60 mL/min/1.73 m²).
• Lower eGFR levels were associated with significantly higher mortality, even after adjusting for baseline factors (P < .0001).
• Adding eGFR improved the C-index (0.837 to 0.843), NRI (3.2%, P < .0001), and IDI (1.3%, P = .007).

Conclusions:

• Estimated glomerular filtration rate is a significant prognostic factor in patients with incident coronary heart disease.
• eGFR provides independent prognostic information beyond established clinical characteristics.
• eGFR enhances the accuracy of risk prediction models for CHD mortality.