Combined association of key risk factors on ischaemic outcomes and bleeding in patients with myocardial infarction

Abstract

Objective: In patients with myocardial infarction (MI), risk factors for bleeding and ischaemic events tend to overlap, but the combined effects of these factors have scarcely been studied in contemporary real-world settings. We aimed to assess the combined associations of established risk factors using nationwide registries.

Methods: Using the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry, patients with invasively managed MI in 2006-2014 were included. Six factors were assessed in relation to cardiovascular death (CVD)/MI/stroke, and major bleeding: age ≥65, chronic kidney disease, diabetes, multivessel disease, prior bleeding and prior MI.

Results: We studied 100 879 patients, of whom 20 831 (20.6%) experienced CVD/MI/stroke and 5939 (5.9%) major bleeding, during 3.6 years median follow-up. In adjusted Cox models, all factors were associated with CVD/MI/stroke, and all but prior MI were associated with major bleeding. The majority (53.5%) had ≥2 risk factors. With each added risk factor, there was a marked but gradual increase in incidence of the CVD/MI/stroke. This was seen also for major bleeding, but to a lesser extent, largely driven by prior bleeding as the strongest risk factor.

Conclusions: The majority of patients with MI had two or more established risk factors. Increasing number of risk factors was associated with higher rate of ischaemic events. When excluding patients with prior major bleeding, bleeding incidence rate increased only minimally with increasing number of risk factors. The high ischaemic risk in those with multiple risk factors highlights an unmet need for additional preventive measures.

Keywords: acute coronary syndromes; risk factors.

Conflict of interest statement

Competing interests: DL reports being an employee at Uppsala University and affiliated with Uppsala Clinical Research Center during the time this work was conducted, but has since been employed by AstraZeneca. BS reports institutional research grants from AstraZeneca, Novartis and Abbott. LPH reports being employed by AstraZeneca. MJ reports lecture fees from AstraZeneca and Pfizer. TJ has received consultant and lecture fees from AstraZeneca, MSD and Aspen. SKJ reports institutional research grants from AstraZeneca.

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Selection of study population. CCU, cardiac care unit; CKD, chronic kidney disease; MI, myocardial infarction; MVD, multivessel disease; SWEDEHEART, Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies; RIKS-HIA, Swedish Register of Information and Knowledge about Swedusg Heart Intensive Care Admissions.

Figure 2

CVD/MI/stroke: Kaplan-Meier estimates of CVD/MI/stroke in relation to risk factors. CKD, chronic kidney disease; CVD, cardiovascular death; MI, myocardial infarction; MVD, multivessel disease.

Figure 3

Major bleeding: Kaplan-Meier estimates of major bleeding in relation to risk factors. CKD, chronic kidney disease; MI, myocardial infarction; MVD, multivessel disease.

Figure 4

Combinations of risk factors and incidence of ischaemic and bleeding events. Panel (A) shows combinations of risk factors (in patients with at least one risk factor). Each black bar represents a combination of risk factors and indicates how many patients have that specific combination. The dots below the black bars indicate which risk factors are present in that group. The blue bars represent the total number of patients having each risk factor. The coloured inset (top right) shows the distribution of risk factor counts in the population. In panel (B) the incidence rates for major bleeding (X axis) and CVD/MI/stroke (Y axis) in relation to combinations of risk factors are shown (lines indicate 95% confidence intervals). In panel (C) the risk factor combinations that do not include prior bleeding are highlighted. (Panels A–C [except inset] include risk factor combinations with at least 30 patients.) CKD, chronic kidney disease; CVD, cardiovascular death; GE, greater than or equal to; MI, myocardial infarction; MVD, multivessel disease.