MO731: Predictors of Early and 1-Year Mortality After an Acute Coronary Event in Haemodialysis Patients
Authors: Castro Pedro , Rita Silva Ana , Lança Alice , Oliveira Nuno , Alves Rui 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Cardiovascular disease (CVD) is the leading cause of mortality in haemodialysis (HD) patients (40%), mainly secondary to a coronary event (17%). According to the European Society of Cardiology (ESC), beta-blockers (BBs), anti-platelets, angiotensin-converting enzyme inhibitors (ACEis)/angiotensin receptor blockers (ARBs) and statins are the cornerstones of CVD prevention. However, a great percentage of dialysis patients remain undermedicated. Our aim is to identify the predictors of mortality in HD patients after an acute myocardial infarction (AMI) during hospitalization and 1 year after the cardiac event.

Methods
We performed an observational retrospective study of all HD patients admitted to the coronary intensive care unit between January 2017 and December 2020 due to a myocardial infarction. Our variables of interest were collected before and after hospital discharge and 1 year after. We assessed patients’ frailty using the clinical frailty scale (CFS) and baseline cardiovascular (CV) risk using ESC’s classification; as we focused in HD patients (very-high risk of CVD), we classified CV risk regardless of the kidney disease. IBM SPSS 23.0 was used to perform statistical analysis; the confidence interval (CI) was set at 95%.

RESULTS
We collected 70 patients (males: n = 51, 73.2%), with a mean age of 70.9 ± 12.2 years and a median time in HD of 73.2 ± 60 months. Identifiable CV risk factors were: dyslipidaemia (98.6%), arterial hypertension (95.7%), heart failure (74.3%), diabetes (57.1%) and obesity (55.7%); mean total cholesterol and low-density lipoprotein cholesterol (LDL) levels were 151 ± 39.6 and 97.5 ± 34.1 mg/dL, respectively. As a result, 81.4% of our sample was classified as having a very high baseline CV risk. Before admission, most patients were on statin therapy (87.1%), but only 34.2% were taking the proper statin class/dosage adjusted to their CV risk. In fact, only 7.1% were previously medicated with all prognosis-modifying drugs (ACEis/ARBs, statins, anti-platelets and BBs). The mean hospitalization stay was 10.3 ± 9 days, and the early mortality rate (30 days post-admission) was 18.6%. Mortality was higher in older patients (72.5 ± 10.3 versus 69.1 ± 10.9 years; P = .3), males (21.6 versus 10.5%), with longer HD vintage (82.8 ± 46.8 versus 70.8 ± 48 months; P = 0.41) and higher CV risk (very-high CV risk, 84.6 versus 80%; P = .7); hypoalbuminemia (serum albumin &lt; 3.0 g/dL) (OR 5.4, 95% CI 1.2–25.1; P = .028) and higher frailty score (CFS ≥ 4) (OR 6.1, 95% CI 1.2–30.0; P = .002) prompt a worse short-term prognosis. The mortality rate after 1 year was 30%, with a median time of 5.6 ± 2.4 months since the cardiac event. Mortality was also higher in older patients (71.5 ± 10 versus 69 ± 10 years; P = .34), males (31.3 versus 26.3%; P = 0.70), with longer dialysis vintage (85.2 ± 45.6 versus 67.2 ± 48; P = .14) and longer hospitalizations (12.8 ± 9.9 versus 9.3 ± 8.3; P = .12). After discharge, patients prescribed with at least three prognosis-modifying drugs had a lower 1-year mortality rate (3.2 versus 26.9%; OR 11, 95% CI 1.2–97.0; P = .003). Hypoalbuminemia (OR 9.4, 95% CI 2.3–4.3’; P = .002) and higher frailty scores (CFS ≥ 4) (OR 4.1, 95% CI 1.2–14.0; P = .025) were associated with worse outcomes.

CONCLUSION
We concluded that most HD patients were undermedicated prior to a coronary event given their baseline CV risk. Despite most studies in HD patients did not find a beneficial long-term effect of starting statin therapy after HD initiation, one must always individualize therapy according to the patient's CV risk. In our series, better-nourished patients with at least three prognosis-modifying drugs had a lower mortality rate, which highlights the importance of these drugs on survival together with optimal nutritional care.