Relationship Between Primary Percutaneous Coronary Intervention, Door-to-balloon Times, and Mortality for Heart Attack Patients Across England

London School of Economics and Political Science42,677 enrolled

Overview

The degree to which elevated mortality associated with weekend or night-time hospital admissions reflects poorer quality of care ('off-hours effect') is a contentious issue. We examined if off-hours admissions for primary percutaneous coronary intervention (PPCI) were associated with higher adjusted mortality and estimated the extent to which potential differences in door-to-balloon (DTB) times-a key indicator of care quality for ST elevation myocardial infarction (STEMI) patients-could explain this association. Nationwide registry-based prospective observational study using Myocardial Ischemia National Audit Project data in England. We examined how off-hours admissions and DTB times were associated with our primary outcome measure, 30-day mortality, using hierarchical logistic regression models that adjusted for STEMI patient risk factors. In-hospital mortality was assessed as a secondary outcome. Our study found that higher adjusted mortality associated with off-hours admissions for PPCI could be partly explained by differences in DTB times.

Study Type

OBSERVATIONAL

Enrollment

42,677

Conditions

Myocardial Infarction

Interventions

Standard Hospital CareOTHER

We described patient characteristics using percentages for categorical data, means and SD or medians and IQRs for normally and non-normally distributed continuous variables, respectively. Statistical comparisons for differences in baseline characteristics among patients admitted during regular hours and off-hours were performed using χ2 tests for categorical variables, t-tests and Wilcoxon rank sum tests for normally and non-normally distributed continuous variables, respectively. DTB times were described using median and IQR based on time of admission. All p values were calculated as two-tailed analyses, using a significance level of 5%.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * STEMI patients admitted from 1 January 2007 to 31 December 2012 * STEMI patients aged over 18 years * STEMI patients admitted directly to '24/7' PPCI-capable hospitals for PPCI * Discharge diagnosis of STEMI * Provision of PPCI based on initial reperfusion strategy Exclusion Criteria: * Hospitals performing less than 20 procedures per year * Hospitals performing PPCIs only during regular hours * Interhospital transfers * PPCIs conducted within 6 hours on hospital arrival

Outcomes

Primary Outcomes

30-day mortality

Time frame: 30 days post-discharge

Secondary Outcomes

In-hospital mortality

Time frame: Patient length of stay in hospital until discharge, an average of 3 days