Hemoglobin/creatinine ratio as long- term prognostic marker in acute coronary syndromes: a praise registry study

Abstract Introduction Anemia and renal impairment are key determinants of adverse outcomes in patients with acute coronary syndrome (ACS). The hemoglobin/creatinine (Hb/Cr) ratio, a simple and universally accessible index that combines these two factors, was found to predict adverse outcomes in patients with cardiovascular disease. There is limited evidence on the performance of the Hb/Cr ratio in predicting long-term adverse outcomes in the specific setting of ACS. Purpose To evaluate the long-term prognostic impact of the Hb/Cr ratio in patients with ACS. Methods Out of the 23,270 ACS patients enrolled in the international PRAISE registry between 2003 and 2019, 3.465 were excluded due to missing data and 19.805 were included in this analysis. The primary endpoint was all-cause mortality at one year follow-up. Secondary endpoints were major bleeding and the composite of all-cause mortality or reinfarction at one year follow-up. A cut-point analysis according to Liu’s method was run to evaluate the best discriminative value of the Hb/Cr ratio for the prediction of all-cause mortality. Results The cut-point analysis showed that a cut-off value of 13.79 represented the most discriminative in predicting all-cause mortality at one year (CI 13.35–14.23; AUC 0.66), and that mortality increased exponentially when the ratio was <12.4. On the basis of this discriminative value, we divided our population into low vs. high Hb/Cr groups. The former included 5,874 (29.7%) patients, while the latter included 13,931 (70.3%). Patients in the low Hb/Cr group were older, more frequently female, and had a higher prevalence of cardiovascular risk factors, comorbidities, and history of coronary artery disease. Conversely, patients in the high Hb/Cr group were mostly men and more frequently admitted with a STEMI diagnosis. One year post-discharge from ACS, all-cause mortality (8.3% vs. 2.3%; p < 0.001), major bleeding (5.4% vs. 2.2%; p < 0.001) and the composite of all-cause mortality or reinfarction (11.6% vs. 4.7%; p < 0.001) were significantly higher in the low Hb/Cr group. Bivariate regression analysis showed that Hb/Cr ratio was inversely associated with all-cause mortality (OR 0.85; CI 0.84 – 0.86; p < 0.0001), major bleeding (OR 0.91; CI 0.89-0.92; p < 0.0001), and the composite of all-cause mortality or reinfarction (OR 0.89; CI 0.88-0.90; p < 0.0001). This association held strongly true even after an extensive adjustment for several covariates, including cardiovascular risk factors, comorbidities, and discharge medical therapy: all-cause mortality (OR 0.95; CI 0.92 – 0.97; p < 0.0001), major bleeding (OR 0.92; CI 0.89-0.95; p < 0.0001), composite of all-cause mortality or reinfarction (OR 0.96; CI 0.94-0.98; p < 0.0001). Conclusions HB/Cr ratio appears to be inversely associated with long-term adverse outcomes among ACS patients. Further research is warranted before routinely considering this index in clinical practice.