Factors associated with rehospitalization in patients with acute myocardial infarction

Temporal Trends and Patient Characteristics Associated with 30-Day Hospital Readmission Rates after a First Acute Myocardial Infarction

BACKGROUND

Limited data exist about relatively recent trends in the magnitude and characteristics of patients who are re-hospitalized after hospital admission for an acute myocardial infarction. This study examined trends in the frequency and sociodemographic and clinical characteristics of patients readmitted to the hospital within 30 days after an initial acute myocardial infarction.

METHODS

We reviewed the medical records of 3116 individuals who were hospitalized for a validated first acute myocardial infarction in 6 study periods between 2003 and 2015 at the 3 major medical centers in central Massachusetts.

RESULTS

The median age of our population was 67 years, and 42% were women. The risk of being readmitted to the hospital within 30 days after an initial acute myocardial infarction increased slightly during the most recent study years after controlling for potentially confounding factors. Overall, older adults and patients with previously diagnosed atrial fibrillation, heart failure, diabetes, chronic kidney disease, stroke, and peripheral vascular disease were at higher risk for being readmitted to the hospital than respective comparison groups. For those hospitalized in the most recent study years of 2011/2015, a higher risk of rehospitalization was associated with a previous diagnosis of chronic kidney disease, peripheral vascular disease, the presence of 3 or more chronic conditions, and having developed atrial fibrillation or heart failure during the patient's hospitalization for a first acute myocardial infarction.

CONCLUSIONS

We identified several groups at higher risk for hospital readmission in whom enhanced surveillance efforts as well as tailored educational and treatment approaches remain needed.

Thirty-day Hospital Readmissions in Patients with Non-ST-segment Elevation Acute Myocardial Infarction

BACKGROUND

Limited data exist about relatively recent trends in the magnitude and characteristics of patients who are rehospitalized shortly after admission for a non-ST-segment elevation acute myocardial infarction (NSTEMI). This observational study describes decade-long trends (1999-2009) in the magnitude and characteristics of patients readmitted to the hospital within 30 days of hospitalization for an incident (initial) episode of NSTEMI.

METHODS

We reviewed the medical records of 2249 residents of the Worcester (Mass) metropolitan area who were hospitalized for an initial NSTEMI in 6 biennial periods between 1999 and 2009 at 3 central Massachusetts medical centers.

RESULTS

The average age of our study population was 72 years, 90% were white, and 46% were women. The proportion of patients who were readmitted to the hospital for any cause within 30 days after discharge for an NSTEMI remained unchanged between 1999 and 2009 (approximately 15%) in both crude and multivariable adjusted analyses. Slight declines were observed for cardiovascular disease-related 30-day readmissions over the 10-year study period. Women, elderly patients, those with multiple chronic comorbidities or a prolonged index hospitalization, and patients who developed heart failure during their index hospitalization were at higher risk for being readmitted within 30 days than respective comparison groups.

CONCLUSION

Thirty-day hospital readmission rates after hospital discharge for a first NSTEMI remained stable between 1999 and 2009. We identified several groups at higher risk for hospital readmission; further surveillance efforts and/or tailored educational and treatment approaches remain needed for these groups.

Processes and outcomes for acute myocardial infarction patients

Purpose

The purpose of this paper is to determine whether process quality indicators for acute myocardial infarction (AMI) one associated with outcome indicators (hospital mortality and early readmission).

Design/methodology/approach

A retrospective cohort study was conducted among patients discharged from three Swiss university hospitals with a primary or secondary International Classification of Diseases, 10th revision (ICD‐10) AMI code in 1999. A total of 1,129 patients' records were abstructed. Demographic characteristics and risk factors at admission were recorded. The main ECG and laboratory findings were further abstracted as well as hospital and discharge management and treatment. The main outcome measure was process quality indicators derived from evidence‐based guidelines, and hospital mortality and early readmissions.

Findings

After exclusions, 577 patients with AMI were eligible for this study. The mean (SD) age was 68.2 (13.9). In the assessment of quality indicators patients with potential contra‐indications were excluded. Among cohorts of “ideal candidates” for specific interventions, aspirin was not prescribed within 24 hours after admission in 33 (6.2 percent) patients. Among those, 17 (51.5 percent) died (p<0.0001). The adjusted OR for no aspirin after admission was 3.61 (95 percent CI 1.11‐11.77) for hospital mortality. Further, 78 (19.5 percent) patients did not receive β‐blockers at discharge. Among them nine (11.5 percent) were readmitted (p=0.133). The adjusted OR for no β‐blockers at discharge was 2.15 (95 percent CI 0.86‐5.41) for readmissions. Among patients with AMI, not prescribing aspirin within 24 hours after admission was associated with hospital mortality. However, process indicators derived from evidence‐based guidelines were not related to early readmission in this study.

Originality/value

The paper stresses the importance of clinicians confronting their decisions with recommendations of evidence‐based guidelines for the management and treatment of AMI patients.

Access to myocardial revascularization procedures: closing the gap with time?

Background

Early access to revascularization procedures is known to be related to a more favorable outcome in myocardial infarction (MI) patients, but access to specialized care varies widely amongst the population. We aim to test if the early gap found in the revascularization rates, according to distance between patients' location and the closest specialized cardiology center (SCC), remains on a long term basis.

Methods

We conducted a population-based cohort study using data from the Quebec's hospital discharge register (MED-ECHO). The study population includes all patients 25 years and older living in the province of Quebec, who were hospitalized for a MI in 1999 with a follow up time of one year after the index hospitalization. The main variable is revascularization (percutaneous transluminal coronary angioplasty or a coronary artery bypass graft). The population is divided in four groups depending how close they are from a SCC (<32 km, 32–64 km, 64–105 km and ≥105 km). Revascularization rates are adjusted for age and sex.

Results

The study population includes 11,802 individuals, 66% are men. The one-year incidence rate of MI is 244 individuals per 100,000 inhabitants. At index hospitalization, a significant gap is found between patients living close (< 32 km) to a SCC and patients living farther (≥32 km). During the first year, a gap reduction can be observed but only for patients living at an intermediate distance from the specialized center (64–105 km).

Conclusion

The gap observed in revascularization rates at the index hospitalization for MI is in favour of patients living closer (< 32 km) to a SCC. This gap remains unchanged over the first year after an MI except for patients living between 64 and 105 km, where a closing of the gap can be noticed.

Spatial variation in the management and outcomes of acute coronary syndrome

Background

Regional disparities in medical care and outcomes with patients suffering from an acute coronary syndrome (ACS) have been reported and raise the need to a better understanding of links between treatment, care and outcomes. Little is known about the relationship and its spatial variability between invasive cardiac procedure (ICP), hospital death (HD), length of stay (LoS) and early hospital readmission (EHR). The objectives were to describe and compare the regional rates of ICP, HD, EHR, and the average LoS after an ACS in 2000 in the province of Quebec. We also assessed whether there was a relationship between ICP and HD, LoS, and EHR, and if the relationships varied spatially.

Methods

Using secondary data from a provincial hospital register, a population-based retrospective cohort of 24,544 patients hospitalized in Quebec (Canada) for an ACS in 2000 was built. ACS was defined as myocardial infarction (ICD-9: 410) or unstable angina (ICD-9: 411). ICP was defined as the presence of angiography, angioplasty or aortocoronary bypass (CCA: 480–483, 489), HD as all death cause at index hospitalization, LoS as the number of days between admission and discharge from the index hospitalization, and EHR as hospital readmission for a coronary heart disease ≤30 days after discharge from hospital. The EHR was evaluated on survivors at discharge.

Results

ICP rate was 43.7% varying from 29.4% to 51.6% according to regions. HD rate was 6.9% (range: 3.3–8.2%), average LoS was 11.5 days (range: 7.5–14.4; median LoS: 8 days) and EHR rate was 8.3% (range: 4.7–14.2%). ICP was positively associated with LoS and negatively with HD and EHR; the relationship between ICP and LoS varied spatially. An increased distance to a specialized cardiology center was associated with a decreased likelihood of ICP, a decrease in LoS, but an increased likelihood of EHR.

Conclusion

The main results of this study are the regional variability of the outcomes even after accounting for age, gender, ICP and distance to a cardiology center; the significant relationships between ICP and HD, LoS and EHR, and the spatial variability in the relationships between ICP and LoS.

An invasive strategy is associated with decreased mortality in patients with unstable angina and non-ST-elevation myocardial infarction: GUSTO IIb trial

There has been much debate concerning an invasive versus a conservative strategy for patients with acute coronary syndromes. The purpose of this study was to determine whether early in-hospital catheterization reduced mortality in patients with unstable angina and non-ST-elevation myocardial infarction. We performed a retrospective analysis of data collected in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIb trial, which compared hirudin and heparin in patients with acute coronary syndromes. We identified 8011 patients with non-ST-segment elevation myocardial infarction and unstable angina who were enrolled in the trial. The primary endpoints were all-cause mortality at 30 days and 1 year. Data were analyzed with multivariate hazards models and propensity scores.After accounting for inception time bias, there were 7897 patients identified, of whom 4536 patients (57%) underwent invasive therapy and 3361 (43%) underwent conservative therapy. Adjusting for propensity scores, the adjusted 30-day mortality for the invasive group was 2.5% compared with 2.7% in the conservative group (P = 0.92); at 1 year, the invasive group had a 6.2% mortality, versus 8.6% in the conservative group (P = 0.005). In a multivariate analysis that adjusted for other clinical factors, an invasive strategy was associated with lower 1-year mortality (hazard ratio = 0.46; 95% confidence interval: 0.10 to 0.84). In patients presenting with acute coronary syndromes, an invasive strategy is associated with improved survival at 1 year even after adjusting for baseline differences.

Effect of anemia on 1-year mortality in patients with acute myocardial infarction

BACKGROUND

Limited data are available on the effect of anemia on mortality in patients with acute myocardial infarction (MI).

METHODS

We examined the association of anemia with mortality at 1 year among 30,341 patients hospitalized with acute MI in 1986 (prethrombolytic era, n = 15,584) and 1996 (thrombolytic era, n = 14,757). The records were obtained from the Myocardial Infarction Data Acquisition System, a database of all patients with MI admitted to nonfederal hospitals in New Jersey.

RESULTS

Anemia was present in 996 patients (6.4%) in 1986 and 1510 patients (10.2%, P <.0001) in 1996. In both years, patients with anemia were older, more frequently female and nonwhite, and more likely to have left ventricular dysfunction, non-Q MI and coronary artery bypass graft. In addition, in 1996, patients with anemia were more likely to undergo percutaneous transluminal coronary angioplasty and less likely to have a history of MI. One-year mortality was lower overall in 1996 compared with 1986 (1996 23.6%, 95% CI 22.9-24.3 vs 1986 24.9%, 95% CI 24.2-25.6, P =.0001). In both years, patients with anemia had significantly higher unadjusted risk for 1-year mortality (RR = 1.40, P =.0001 in both years). However, after controlling for demographics, left ventricular dysfunction, arrhythmias, Q versus non-Q MI, comorbid conditions, and revascularization procedures in a multivariable regression model, 1-year mortality in the anemia group was similar to the nonanemia group in both years.

CONCLUSION

In the Myocardial Infarction Data Acquisition System database, anemia appears to have no significant direct effect on 1-year mortality. The higher unadjusted mortality observed among patients with acute MI and anemia is probably the result of older age, higher comorbidity, and more left ventricular dysfunction.

Risk stratification post-myocardial infarction: is early coronary angiography the more effective strategy?

The primary management strategy for the post-myocardial infarction patient continues to be controversial despite published guidelines. In part, this is the consequence of study designs that are not directly applicable to individual patients, but also to the rapidly changing pharmacological and mechanical device armamentarium that rapidly renders clinical trial results obsolete within a few years. This review attempts to highlight those areas where there is consensus as well as to explicate those situations where common clinical practice appears to be in conflict with accepted guidelines.

Analyzing hospital readmissions using statewide discharge databases

Hospital readmissions are an important indicator of the outcomes of care as well as a source of unnecessary health care expenditures. This study focused on development of a uniform algorithm for identification of hospital readmission data. It involved development of a uniform definition of readmissions which could be applied to multiple statewide computer databases. Through this approach, comparable readmit data were generated for use in benchmarking and quality improvement activities.

Clinical epidemiology of acute myocardial infarction

In the United States by mid-century, cardiovascular disease accounted for more than half of all deaths. In the second half of this century, 85% of reduction in age-adjusted mortality rates from all causes can be ascribed to the decline in death from cardiovascular disease and stroke. Approximately half of such dramatic decline in mortality rates from ischemic heart disease (IHD) can be explained by primary and secondary prevention and half by therapeutic improvements. Epidemiology of therapeutic regimens in acute myocardial infarction (AMI) indicates substantial increases in the use of thrombolytic therapy, aspirin, beta-blockers and, in some countries, coronary angioplasty. The long-term results of several thrombolytic trials have shown the persistence of early benefit until 10 years after AMI. However, approximately half of the patients with AMI are admitted to the hospital too late to fully benefit from thrombolytic therapy, and one fourth of eligible patients do not receive any form of reperfusion. Primary angioplasty is advocated by some as the treatment of choice in AMI. The present results are not convincing enough to induce the enormously complex and costly reorganization of the health system, allowing the immediate access to coronary angiography for all or most patients with AMI. However, stenting the infarct coronary artery at the site of previous occlusion appears to improve the immediate and medium-term results of coronary revascularization procedures. Approximately half of the AMI survivors are rehospitalized within 1 year after the index event, and postinfarction mortality rate remains exceedingly high. After AMI, prognostic and therapeutic procedures have been introduced in the absence of evidence from controlled trials of their effectiveness profile. Outcome research is needed to standardize effective post-AMI policies. Moreover, new strategies are needed to reduce the incidence and mortality rates of acute ischemic events. A number of new candidate risk factors for IHD are emerging; they are associated with endothelial dysfunction, thrombogenic state, and inflammatory state. It is hoped that advances in molecular approach to cardiovascular disease, molecular genetics and transgenic techniques will allow better understanding and more effective therapeutic strategies to prevent and control IHD.