Waiting times, revascularization modality, and outcomes after acute myocardial infarction at hospitals with and without on-site revascularization facilities in Canada

Association of Neighborhood-Level Marginalization With Health Care Use and Clinical Outcomes Following Hospital Discharge in Patients Who Underwent Coronary Catheterization for Acute Myocardial Infarction in a Single-Payer Health Care System

BACKGROUND

Canadian data suggest that patients of lower socioeconomic status with acute myocardial infarction receive less beneficial therapy and have worse clinical outcomes, raising questions regarding care disparities even in universal health care systems. We assessed the contemporary association of marginalization with clinical outcomes and health services use.

METHODS

Using clinical and administrative databases in Ontario, Canada, we conducted a population-based study of patients aged ≥65 years hospitalized for their first acute myocardial infarction between April 1, 2010 and March 1, 2019. Patients receiving cardiac catheterization and surviving 7 days postdischarge were included. Our primary exposure was neighborhood-level marginalization, a multidimensional socioeconomic status metric. Neighborhoods were categorized by quintile from Q1 (least marginalized) to Q5 (most marginalized). Our primary outcome was all-cause mortality. A proportional hazards regression model with a robust variance estimator was used to quantify the association of marginalization with outcomes, adjusting for risk factors, comorbidities, disease severity, and regional cardiologist supply.

RESULTS

Among 53 841 patients (median age, 75 years; 39.1% female) from 20 640 neighborhoods, crude 1- and 3-year mortality rates were 7.7% and 17.2%, respectively. Patients in Q5 had no significant difference in 1-year mortality (hazard ratio [HR], 1.08 [95% CI, 0.95-1.22]), but greater mortality over 3 years (HR, 1.13 [95% CI, 1.03-1.22]) compared with Q1. Over 1 year, we observed differences between Q1 and Q5 in visits to primary care physicians (Q1, 96.7%; Q5, 93.7%) and cardiologists (Q1, 82.6%; Q5, 72.6%), as well as diagnostic testing. There were no differences in secondary prevention medications dispensed or medication adherence at 1 year.

CONCLUSIONS

In older patients with acute myocardial infarction who survived to hospital discharge, those residing in the most marginalized neighborhoods had a greater long-term risk of mortality, less specialist care, and fewer diagnostic tests. Yet, there were no differences across socioeconomic status in prescription medication use and adherence.

CAEP 2021 Academic Symposium: recommendations for addressing racism and colonialism in emergency medicine

Purpose

Racism and colonialism impact health, physician advancement, professional development and medical education in Canada. The Canadian Association of Emergency Physicians (CAEP) has committed to addressing inequities in health in their recent statement on racism. The objective of this project was to develop recommendations for addressing racism and colonialism in emergency medicine.

Methods

The authors, in collaboration with a 40 member working group, conducted a literature search, held a community consultation, solicited input from expert medical, academic and community advisors, conducted a national survey of emergency physicians, and presented draft recommendations at the 2021 CAEP Academic Symposium on Equity, Diversity and Inclusion for a live facilitated discussion with a post-session survey.

Results

Sixteen recommendations were generated in the areas of patient care, hospital and departmental commitment to Equity, Diversity, and Inclusion, physician advancement, and professional development and medical education.

Conclusion

Emergency physicians are uniquely positioned to promote equity at each encounter with patients, peers and learners. The 16 recommendations presented here are practical steps to countering racism and colonialism everyday in emergency medicine.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43678-021-00244-2.

Socioeconomic Status, Mortality, and Access to Cardiac Services After Acute Myocardial Infarction in Canada: A Systematic Review and Meta-analysis

Background

Low socioeconomic status (SES) is an important prognosticator for those with acute myocardial infarction (AMI), having previously been described to be associated with increased short-term mortality. Whether this effect persists over time, and whether access to cardiac interventions is equitable within Canada’s universal health care system, remains unknown.

Methods

We conducted a systematic review to determine the associations of SES with mortality and access to a spectrum of interventions including cardiac catheterization, revascularization, and cardiac rehabilitation. Electronic databases (EMBASE and MEDLINE) were searched in March 2019 and December 2019. Original studies from Canada examining associations between SES and any of the above outcomes in AMI patients were included. Meta-analyses were conducted using random effects models.

Results

Nineteen studies were included, 11 of which could be meta-analyzed. Low SES was associated with a 48% and 34% increase in short-term and intermediate-term mortality, respectively. There was a trend toward increased long-term mortality more than 1-year post-event (pooled odds ratio [OR] 1.34 [95% confidence interval {CI} 0.95-1.88]). Low SES was also associated with lower rates of cardiac catheterization (pooled OR 0.80 [95% CI 0.65-0.99]) and revascularization (pooled OR 0.76 [95% CI 0.63-0.90]) post-AMI. Studies on cardiac rehabilitation showed reduced access and participation in low-SES groups.

Conclusions

Low SES is associated with not only increased mortality post-AMI, but also reduced access to cardiac interventions that have demonstrated benefits for mortality and morbidity. Interventions that improve access to catheterization, revascularization, and cardiac rehabilitation for low-SES populations are needed if true equitable care in Canada is desired.

National Interhospital Transfer for Patients With Acute Cardiovascular Conditions

Background

Treatment of ST-elevation myocardial infarction (STEMI) in Canada is protocolized, and timely patient transfer can improve outcomes. Population-based processes of care in Canada for other cardiovascular conditions remain less clear. We aimed to describe the interhospital transfer of Canadian patients with acute cardiovascular disease.

Methods

We reviewed the Canadian Institute for Health Information Discharge Abstract Database for adult patients hospitalized with acute cardiovascular disease between 2013 and 2018. We compared patient characteristics and clinical outcomes based on transfer status (transferred, nontransferred) and presenting hospital (teaching, large community, medium community, and small community hospitals). The primary outcome of interest was in-hospital mortality.

Results

There were 476,753 patients with primary acute cardiovascular diagnoses, 48,579 (10.2%) of whom were transferred. Transferred patients were more frequently younger, male, and had fewer comorbidities. The most common diagnoses among transferred patients were non-STEMI (44.2%), STEMI (29.0%), and congestive heart failure (9.4%). Using teaching hospitals as a reference, transfer to large and medium community hospitals was associated with lower hospital mortality (adjusted odds ratio: 0.83, 95% confidence interval: 0.75-0.91 and 0.45, 95% confidence interval: 0.39-0.52, respectively).

Conclusions

Approximately 10% of patients with acute cardiovascular conditions are transferred to another hospital. Patient transfer may be associated with lower in-hospital mortality, with possible variability based on diagnosis, comorbidities, hospital of origin, and destination hospital. Further investigation into the optimization of care for patients with acute cardiovascular disease, including transfer practices, is warranted as regionalized care models continue to develop.

Regional differences in coronary revascularization procedures and outcomes: a nationwide 11-year observational study

Aims

The study investigated whether regional differences in choice of coronary revascularization affected outcomes in Sweden.

Methods and results

We conducted a prospective nationwide study of outcome in patients undergoing coronary artery bypass grafting (CABG, n = 47 065) or percutaneous coronary intervention (PCI, n = 140 945) from 2001 through 2011, tracked for a median of 5 years. During this period, the proportion of CABG in revascularization procedures decreased nationwide from an average of 38% to 18%e. Three-vessel disease and left main stem coronary artery stenosis were more common among CABG patients than in PCI patients. In both males and females, all-cause mortality was higher in CABG patients than in PCI patients, while repeat PCI was performed more frequently in the PCI group. CABG proportions in 21 counties ranged from 13% to 42% in females and males. The combined outcomes of repeat revascularization, non-fatal acute myocardial infarction, and death during the tracking period was recorded in 151 936 patients without ST-elevation myocardial infarction after PCI (n = 37 820, 36%) and CABG (n = 18 903, 40%). The multivariable adjusted risk of combined outcomes was higher after both PCI and CABG in both females and males in the three quartiles of counties with a smaller proportion of CABG than in the quartile of counties with the highest proportion of CABG. Similar patterns persisted after including only mortality in the analyses.

Conclusion

There are subgroups of patients who have prognostic benefits of CABG in addition to symptomatic improvement that is well documented with both PCI and CABG.

Outcomes and transfer patterns for first Non-ST-elevation myocardial infarction (NSTEMI): comparisons between community and tertiary care hospitals

BACKGROUND

Transfer patterns, procedure rates, and outcomes of patients with non-ST-segment elevation myocardial infarction (NSTEMI) presenting to Canadian community hospitals are not well understood.

METHODS

We documented all patients admitted to British Columbia (BC) hospitals with a primary diagnosis of NSTEMI between 2007 and 2008. Patients were divided by admitting hospital type into tertiary care hospitals, nonremote community hospitals, and remote community hospitals. The aims were to compare transfer rates and time to transfer to a tertiary hospital as well as procedure rates and outcomes at index admission, at 30 days, and at 1 year.

RESULTS

The mean transfer rates to a tertiary hospital were 72.6% for nonremote and 57.1% for remote community hospitals (P < 0.001). Times to and rates of cardiac procedures differed significantly among these 3 hospital types. Admission to a nonremote or remote community hospital was associated with similar 1-year mortality compared with admission to a tertiary care hospital (nonremote hospitals, adjusted odds ratio [OR], 0.87; P = 0.26; remote hospitals, adjusted OR, 1.19; P = 0.33). At 1 year, admission to a nonremote community hospital was associated with a lower composite outcome of death or readmission for acute myocardial infarction (AMI) (adjusted OR, 0.80; P = 0.04).

CONCLUSIONS

One-year mortality rates were not different between patients with NSTEMI admitted to BC community and tertiary care hospitals; however, the rate of readmission for AMI/death was significantly less in patients admitted to nonremote community hospitals. This should prompt the evaluation of key outcomes in NSTEMI in other community hospital settings.

Ambulatory surveillance of patients referred for cardiac rehabilitation following cardiac hospitalization: a feasibility study

BACKGROUND

Our purpose was to examine the feasibility of implementing an ambulatory surveillance system for monitoring patients referred to cardiac rehabilitation following cardiac hospitalizations.

METHODS

This study consists of 1208 consecutive referrals to cardiac rehabilitation between October 2007 and April 2008. Patient attendance at cardiac rehabilitation, waiting times for cardiac rehabilitation, and adverse events while waiting for cardiac rehabilitation were tracked by telephone surveillance by a nurse.

RESULTS

Among the 1208 consecutive patients referred, only 44.7% attended cardiac rehabilitation; 36.4% of referred patients were known not to have attended any cardiac rehabilitation, while an additional 18.9% of referred patients were lost to follow-up. Among the 456 referred patients who attended the cardiac rehabilitation program, 19 (4.2%) experienced an adverse event while in the queue (13 of which were for cardiovascular hospitalizations with no deaths), with mean waiting times of 20 days and 24 days among those without and with adverse events, respectively. Among the 440 referred patients who were known not to have attended any cardiac rehabilitation program, 114 (25.9%) had adverse clinical events while in the queue; 46 of these events required cardiac hospitalization and 8 patients died.

CONCLUSIONS

Ambulatory surveillance for cardiac rehabilitation referrals is feasible. The high adverse event rates in the queue, particularly among patients who are referred but who do not attend cardiac rehabilitation programs, underscores the importance of ambulatory referral surveillance systems for cardiac rehabilitation following cardiac hospitalizations.

Temporal Trends in Cardiogenic Shock Treatment and Outcomes Among Ontario Patients With Myocardial Infarction Between 1992 and 2008

Background—

Clinical trials have demonstrated that emergent revascularization improves survival of patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). However, rates of uptake and impact on outcomes remain uncertain.

Methods and Results—

We identified 9750 patients (3.1%) with CS among 311 183 AMI patients in the Ontario Myocardial Infarction Database between 1992 and 2008 (55.8% men; mean age, 73 years). CS incidence, mortality, revascularization, and transfers from nonrevascularization sites were studied over 3 periods: period 1, before the 1999 American College of Cardiology/American Heart Association AMI guidelines recommending urgent revascularization for patients <75 years; period 2 (1999 to 2004); and period 3, after 2004 guideline revisions suggesting revascularization for patients ≥75 years. Compared with period 1, period 3 was marked by significantly lower CS incidence (3.4% versus 2.6%), increase in transfers from nonrevascularization sites (10.6% versus 23.9%), and adjusted 1-year mortality rates (81.9% versus 71.5%; all comparisons statistically significant). Admission to nonrevascularization sites was associated with lower revascularization rates (8.6% versus 46.6%, P <0.001) and higher adjusted 1-year mortality rates (78.8% [95% confidence interval, 77.4 to 80.2] versus 71.9% [95% confidence interval, 69.8 to 74.1]). Patients ≥75 years of age were less likely to be revascularized or transferred. The greatest increase in transfers from nonrevascularization sites occurred between periods 1 and 2 for patients <75 years (16.5% to 31.4%; P <0.001) and between periods 2 and 3 for patients ≥75 years (6.7% to 12.8%; P <0.001).

Conclusions—

Publication of American College of Cardiology/American Heart Association guidelines was followed by increased revascularization and transfer rates, along with declining mortality rates among Ontario AMI patients with CS. These results highlight possibilities for further improvement, particularly among patients eligible for transfer from nonrevascularization sites.

Specialized cardiological care may be overutilized in urban areas of Quebec

BACKGROUND

Urban/rural differences in secondary cardiovascular disease (CVD) events have previously been observed for Québec. These differences could be attributable to differential utilization of specialized cardiological care, such as revascularization procedures and visits to cardiologists; if this were the case, policies to increase utilization in rural areas would be indicated.

DESIGN

This is a population-based cohort study.

METHODS

We analysed mortality and hospital re-admission in Québec within 1 year after an initial cardiovascular event in relation to urban/rural location and specialized care utilization, controlling for demography, comorbidities, and cumulative hospitalization.

RESULTS

Analysis showed higher hospital re-admissions and slightly lower CVD mortality in rural areas, as well as less use of specialized care in rural areas. However, urban/rural differentials were not attributable to differences in utilization of care. Paradoxically, comorbidities were lower among patients who saw specialists.

CONCLUSIONS

Ultimately, urban/rural differences in secondary CVD outcomes were not attributable to differences in care utilization or our measures of underlying health status, and were likely due to cultural or lifestyle factors that are both hard to model and hard to change through policy. There appears to be overutilization of specialized care in urban areas, an issue which requires further study. Our results suggest that substantial caution is required when interpreting health service usage data and that critical factors in the relationship between specialized cardiological care and outcomes are still poorly understood at a population level.

Trends in postacute myocardial infarction management and mortality in patients with diabetes. A population-based study from 1995 to 2001

OBJECTIVE

To compare trends in coronary revascularization use and case fatality rate (CFR) following acute myocardial infarction in patients with and without diabetes.

METHODS

A retrospective study of 77,552 patients, 20 years of age or older (25% with diabetes), who were hospitalized for a first acute myocardial infarction in the province of Quebec between April 1995 and December 2001 was conducted. Administrative databases were used to identify patients and assess outcomes.

RESULTS

Compared with patients without diabetes, patients with diabetes underwent more coronary artery bypass graft (CABG) surgeries (11.1% versus 8.3%; P<0.0001) but fewer percutaneous coronary interventions (17.1% versus 20.2%; P<0.0001). The use of percutaneous coronary intervention increased substantially over time in both populations, driven mainly by an increase during the index admission (20.6% versus 16.6% per year; P=0.1144 in patients with and without diabetes, respectively). The use of CABG during the index admission increased markedly among patients with diabetes compared with those without (10.3% versus 5.3% per year; P=0.0072); however, at one-year following discharge, CABG use remained stable in patients with diabetes and fell in those without (-0.7% versus -5.3% per year; P=0.2046). Concomitantly, patients with diabetes presented a similar decline in CFR compared with patients without diabetes. The decline was more pronounced during the index admission (-5.0% versus -4.1% per year; P=0.282) than at one-year following discharge (-2.5% versus -2.5% per year; P=0.629) in patients with and without diabetes, respectively. However, fatal outcome remained higher in patients with diabetes than without, with an adjusted RR of 1.21 (95% CI 1.18 to 1.24) at one-year follow-up.

CONCLUSION

Overall, coronary revascularization use and CFR improved over time in patients with diabetes. Nevertheless, the mortality rate in patients with diabetes remains higher than in patients without diabetes, indicating that additional progress is required to improve the poorer prognosis in this population.

Impact of clinical urgency, physician supply and procedural capacity on regional variations in wait times for coronary angiography

Background

Despite universal health care, there continues to be regional access disparities to coronary angiography in Canada. Our objective was to evaluate the extent to which demand-side factors such as clinical urgency/need, and supply-side factors, as reflected by differences in physician and procedural supply account for these inequalities.

Methods

Our cohort consisted of 74,254 consecutive patients referred for coronary angiography in Ontario, Canada between April 1^st 2005 and March 31^st 2006, divided into three urgency strata based on a clinical urgency scale. Cox-proportional hazard models were developed, adjusting for age, gender, socioeconomic status (SES), region, and urgency score, with greater hazard ratios (HR) indicating shorter wait times. To evaluate mediators of any residual wait-time differences, we examined the influence of the regional supply of cath lab facilities, invasive cardiologists and general practitioners (GP).

Results

We found that the urgency score was a significant predictor of wait time in all three strata (urgent patients: HR 1.61 for each unit increase in patient urgency (95% Confidence interval (CI) 1.55-1.67); semi-urgent patients: HR 1.55 (95% CI 1.44-1.68); elective patients: HR 1.13 (95% CI 1.08-1.18)). After accounting for clinical need/urgency, regional wait time differences persisted; these were most consistently associated with variation in cath lab supply. The impact of invasive cardiologist supply was restricted to urgent patients while that of GP supply was confined to semi-urgent and elective patients.

Conclusion

We found that there remained significant regional disparities in access to coronary angiography after accounting for clinical need. These disparities are partially explained by variations in supply of both procedural capacity and physician services, most notably in elective and semi-urgent patients.

The effect of place of residence on access to invasive cardiac services following acute myocardial infarction

BACKGROUND

The Canadian health care system is mandated to provide reasonable access to health care for all Canadians regardless of age, sex, race, socioeconomic status or place of residence. In the present study, the impact of place of residence in Nova Scotia on access to cardiac catheterization and long-term outcomes following an acute myocardial infarction (MI) were examined.

METHODS

All patients with an acute MI who were hospitalized between April 1998 and December 2001 were identified. Place of residence was defined by postal code and separated into three categories: metropolitan area (MA); nonmetropolitan urban area (UA); and rural area (RA). Rates of and waiting times for cardiac catheterization were determined, as were risk-adjusted long-term rates of mortality and readmission to the hospital.

RESULTS

A total of 7351 patients were hospitalized with an acute MI during the study period. Rates of cardiac catheterization differed across the three groups (MA 45.6%, UA 37.3%, RA 37.3%; P<0.0001), as did mean waiting times (MA 15.0 days, UA 32.1 days, RA 28.7 days) (P<0.0001). After adjusting for differences among patients, residence in either UA or RA emerged as an independent predictor of lower rates of cardiac catheterization (UA: hazard ratio [HR] 0.77, P<0.0001; RA: HR 0.75, P<0.0001), greater waiting times (UA: an additional 14.1 days, P<0.0001; RA: an additional 10.8 days, P<0.0001) and increased long-term rates of readmission (UA: HR 1.24, P=0.0001; RA: HR 1.12, P=0.04).

CONCLUSION

In patients admitted with an acute MI, residence outside of an MA was associated with diminished rates of cardiac catheterization, longer waiting times and increased rates of readmission. Despite universal health care coverage, Canadians are subject to significant geographical barriers to cardiac catheterization with associated poorer outcomes.

Effects of exercise on the duration of diastole and on interventricular phase differences in patients with hypertrophic cardiomyopathy: relationship to cardiac output reserve

BACKGROUND

Our study sought to characterize the effect of exercise on the duration of left ventricular (LV) diastole and interventricular dyssynchrony in patients with hypertrophic cardiomyopathy (HCM). We hypothesized that an abnormally shortened diastolic time may adversely affect cardiac performance.

METHODS

We studied 49 symptomatic patients with HCM during incremental exercise. Twenty-nine patients had obstructive disease (HOCM) and 20 no resting or provocable gradient (HNCM). Right heart catheterization and high temporal resolution radionuclide angiography were simultaneously performed. The loss of diastolic time per beat (LDT(RR)) was quantified using a regression equation obtained from a healthy control group (n = 30).

RESULTS

During rest and peak exercise, a significant shortening of the relative duration of LV diastole (35.6 +/- 5 vs. 38.0 +/- 3 s/min and 29.3 +/- 6 vs. 32.4 +/- 3 s/min; P < or = .02) and an increased interventricular phase delay were evident in patients with HOCM compared to controls. Baseline and peak exercise LDT(RR) values were inversely related to cardiac output reserve and exercise duration. In multivariate analysis, LDT(RR) at peak exercise was identified as an independent predictor of cardiac output reserve.

CONCLUSIONS

In HOCM, baseline abnormalities of the relative duration of LV systolic and diastolic time aggravate during exercise. The disproportionate shortening of diastolic time may significantly impair cardiac efficiency by restricting diastolic filling.

The influence of a "culture of referral" on access to care in rural settings after myocardial infarction

Access to care is an issue for rural people who require tertiary care following a myocardial infarction (MI). Access to specialized cardiac health services is contingent upon referral to tertiary care in urban centers. Using a critical ethnographic approach, rural women, their nurses and physicians were interviewed to explore how rurality affected women's referral and access to care following a MI. Findings reflect that a previously undocumented culture of referral that was shaped by human factors influenced access to care. The culture of referral reflected an urban-centric approach to the provision of cardiovascular services and a medical hierarchy within the referral system. The findings extend conceptual understandings of access to health care in relation to rural populations.

Timing of bypass surgery in stable patients after acute myocardial infarction

OBJECTIVES

To determine the optimal timing for bypass surgery in stable patients after acute myocardial infarction (MI).

BACKGROUND

Coronary artery bypass graft surgery (CABG) is a proven treatment for coronary artery disease. Because of the hypothesized risk of hemorrhagic transformation, it had become common practice to wait four to six weeks after MI. Recently, improvements in surgical and perioperative management, as well as an increase in pre-CABG in-hospital waiting times and excess burden on health care resources, have pushed surgeons to operate earlier. The optimal timing for a stable patient to undergo CABG after MI is unclear, because there have been no randomized trials to answer this question.

METHODS

The published literature comparing early versus late surgical revascularization procedures in stable post-MI patients was reviewed.

RESULTS

No randomized, prospective trials were found; however, several retrospective studies were identified. Most series examining Q wave MIs showed that mortality is higher in the early stages post-MI and progressively decreases with time post-MI. When studies examined non-Q wave MIs separately, there appeared to be less of a mortality difference between early and late surgical revascularization. There was a large disparity between the definitions of early surgery post-MI among the studies, some as early as 6 h and others up to eight days. Factors that increased mortality include abnormal left ventricular function and urgency of surgery, and some studies found risk models helpful to define increased risk after infarction. The possible increased risk of early surgery may be balanced against the potential for improved remodelling, improved quality of life and decreased hospital stay costs.

CONCLUSIONS

There is a need for a randomized, prospective trial examining the optimal timing for CABG in stable post-MI patients.

ICD-10 adaptations of the Ontario acute myocardial infarction mortality prediction rules performed as well as the original versions

OBJECTIVE

To derive and validate an International Classification of Diseases-10 (ICD-10) version of the Ontario Acute Myocardial Infarction (AMI) mortality prediction rules, used to adjust for case-mix differences in studies of AMI patients using administrative data.

STUDY DESIGN AND SETTING

We linked the records of all Ontario patients admitted with AMI (2002-2004) with mortality data. The original ICD-9 codes were mapped to ICD-10-CA (Canada) codes using both a translation produced by coding experts and a manual search of codes; the final codes were determined by consensus. Comorbidity prevalence and mortality rates were calculated. Multivariable logistic regression models were used to predict 30-day and 1-year mortality and the C-statistic was used to evaluate the discrimination of the models.

RESULTS

We identified 37,271 AMI patients. The most common comorbidities were heart failure and dysrhythmias; 30-day and 1-year mortality rates were 12.3% and 21.8%, respectively; and mortality rates were highest among patients with shock, cancer, and acute renal failure. The C-statistics were 0.77 and 0.80, compared with 0.78 and 0.79 in the ICD-9 version, for 30-day and 1-year mortality, respectively.

CONCLUSION

An ICD-10 version of the AMI mortality prediction rules predicted 30-day and 1-year mortality as well as the original ICD-9 version.

Angiographic perfusion score in patients treated with PCI at late angiography following fibrinolytic administration for ST-segment elevation myocardial infarction is associated with morbidity and mortality at 30 days

BACKGROUND

Among patients with ST-segment elevation myocardial infarction (STEMI), evidence of restoration of both normal epicardial arterial flow and myocardial perfusion early after the administration of fibrinolytic agents has been associated with improved clinical outcomes. In STEMI patients treated with fibrinolytic therapy and scheduled for angiography later during hospital admission, however, the association of later indices of flow and perfusion with clinical outcomes has not been assessed.

METHODS

Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis in Myocardial Infarction (CLARITY-TIMI) 28 enrolled 3,491 STEMI patients treated with fibrinolytic therapy. Angiography was scheduled 48-192 h (median 84) after randomization. The Angiographic Perfusion Score (APS) (the sum of the TIMI Flow Grade and Myocardial Perfusion Grade before and after percutaneous coronary intervention (PCI), range of 0-12) was assessed in the 1,460 patients treated with PCI at late angiography, and its association with morbidity and mortality at 30 days was examined.

RESULTS

Full perfusion, defined as an APS of 10-12, was associated with the lowest mortality (0.8%), while partial perfusion (APS 4-9) (2.3%) and failed perfusion (APS 0-3) (18.0%) were associated with a higher incidence of mortality at 30 days (P < 0.001 for full perfusion vs. partial perfusion, P < 0.0001 for overall trend). In addition, full perfusion was associated with a lower incidence of recurrent myocardial infarction (MI), a composite of death and MI, recurrent myocardial ischemia, ventricular tachyarrhythmia, congestive heart failure and shock (P < 0.05 for all trends).

CONCLUSION

Among STEMI patients treated with late PCI following fibrinolytic therapy, higher APS is associated with reduced morbidity and mortality.

Regional Differences in Process of Care and Outcomes for Older Acute Myocardial Infarction Patients in the United States and Ontario, Canada

Background— Previous comparisons of acute myocardial infarction (AMI) treatment between the United States and Canada are limited because they compared selected patients from randomized trials, used administrative data that lacked clinical detail, or did not consider regional differences in AMI treatment.

Methods and Results— We compared medication use, invasive cardiac procedure use, and 30-day risk-standardized mortality rates of 38 886 fee-for-service Medicare beneficiaries hospitalized with AMI in the United States and 5634 similarly aged patients in Ontario, Canada, from 1998 and 2001. Baseline characteristics and illness severity across the US regions and Ontario were not substantially different. Cardiac catheterization use in AMI patients was significantly higher in the United States compared with Ontario (38.7% versus 16.8%, P <0.001), but significant regional variations existed, in which the northeastern United States had significantly lower utilization rates (25.6%) compared with other US regions. β-Blocker use among ideal candidates was highest in the northeastern United States (77.6% versus 69.7% in the United States as a whole, P <0.001) and angiotensin-converting enzyme inhibitor use was highest in Ontario (69.1% versus 58.2% in the United States, P <0.001). Risk-standardized mortality rates at 30 days were not substantially different across the regions.

Conclusions— Previous studies have suggested a clear divergence in invasive cardiac therapy for AMI patients between the United States and Canada on the basis of health care financing and structural differences. Our findings of similar treatment patterns in the northeastern United States and Ontario suggest that regional practices may have a greater impact on treatment patterns than the respective health care delivery systems.

Effects of socioeconomic status on mortality after acute myocardial infarction

PURPOSE

To assess the effects of socioeconomic status on mortality in patients with acute myocardial infarction.

MATERIAL AND METHODS

We studied a retrospective cohort of 5622 patients who presented to a hospital emergency department with an initial episode of acute myocardial infarction between April 1998 and March 2002 in the Province of Alberta, Canada. Our main outcome measure was 1-year all-cause mortality following the index emergency department visit; we used socioeconomic status (measured by neighborhood median household income) as our main predictor after controlling for patient and hospital characteristics and revascularization.

RESULTS

Socioeconomic status profoundly affected the rate of emergency department presentation and the process and outcome of acute myocardial infarction care. In patients belonging to the lowest versus the highest socioeconomic status quartile, the risk of presenting to the emergency department was 72% higher (P <.001); at 1 year, revascularization was lower (36% vs 48%, P <.001), and mortality higher (19.1% vs 9.1%, P <.001). Socioeconomic status was independently associated with 1-year mortality after adjustment for baseline characteristics and 1-year revascularization, and socioeconomic status was especially influential in non-revascularized patients.

CONCLUSIONS

Given the influence of socioeconomic status on mortality after acute myocardial infarction and the key role of revascularization in modulating this relationship, our study has important implications for access to and process of cardiac care.

Access to revascularization among patients with acute myocardial infarction in New York City--impact of hospital resources

Timely revascularization can improve survival in patients with acute myocardial infarction. Identification of factors associated with increased use of revascularization in appropriate patients could improve outcomes. Using New York City hospital discharge records for 1988-1992 and 1998-2002, we determined revascularization rates for patients hospitalized with MI by neighborhood. Odds ratios for revascularization were estimated using a spatial model adjusting for neighborhood sociodemographic characteristics, while accounting for similarities in the rate of revascularization among geographically adjacent neighborhoods. Only 16 out of 112 New York City hospitals performed coronary revascularization. They were located in 14 of 41 neighborhoods. In general, patients living in neighborhoods with higher percentages of patients admitted to hospitals capable of revascularization service were more likely to be revascularized than those in neighborhoods with low percentages of patients admitted to hospitals with revascularization resources. This was true regardless of neighborhood availability of revascularization, after accounting for neighborhood socioeconomic characteristics and patients' clinical status. Revascularization rates in New York City increased from 1988-1992 to 1998-2002 in every neighborhood and as a whole from 103 to 326 per 1,000 hospitalized AMI patients. This increase was not explained by the addition of new revascularization services. Thus, in New York City, where only certain hospitals can perform revascularization, efficient delivery of patients to hospitals with these resources appears to increase the likelihood of revascularization performance among AMI patients without increasing the number of new hospitals capable of revascularization.

Magnetic resonance imaging of delayed enhancement in hypertrophic cardiomyopathy: relationship with left ventricular perfusion and contractile function

PURPOSE

The aim of the study was to analyze the relationship between myocardial delayed enhancement, first-pass perfusion, and contractile function in hypertrophic cardiomyopathy (HCM) patients, using MR.

METHODS

Fifty-three patients diagnosed with HCM were prospectively examined using a 1.5-T MR unit. Multiphase gradient-echo sequences were performed to study global left ventricular function, wall thickness, and left ventricular mass. Myocardial tissue tagging was conducted to evaluate contractile function. T1-weighted inversion-recovery sequences were obtained at rest to study myocardial contrast enhancement at first pass and delayed enhancement 10 minutes later.

RESULTS

Delayed enhancement found in 30 patients (56.6%) was most commonly seen in hypertrophic segments. Nine patients exhibited delayed enhancement in segments with normal wall thickness (<15 mm). Sixteen patients (30.1%) showed first-pass perfusion defects at rest, which were associated with significantly lower stroke volume (P<0.05) and lower cardiac output (P<0.01). The hypokinetic segments found in 16 patients (30.1%) were significantly thicker at end diastole (P<0.01). Delayed enhancement correlated positively with perfusion defects (r=0.5, P<0.01) and hypokinetic segments (r=0.3, P<0.05).

CONCLUSION

Delayed myocardial enhancement is most commonly found in hypertrophic segments but also can be seen in segments with normal wall thickness. Perfusion defects at rest and impaired contractile function are related abnormalities with delayed myocardial enhancement. Further studies are necessary to assess the role of myocardial tagging, first-pass perfusion, and delayed enhancement in risk stratification for patients with HCM.

Is delayed facilitated percutaneous coronary intervention better than immediate in reperfused myocardial infarction? Six months follow up findings

BACKGROUND

There are several new strategies proposed to improve the outcome of patients with ST-elevation myocardial infarction (STEMI). One approach is the resurgent use of facilitated percutaneous coronary interventions (PCI). Until recently, deciding whether immediate PCI after combined treatment (facilitated PCI) is more appropriate than delayed PCI (short time) has not been investigated. The aim of this study, therefore, was to investigate the outcomes in patients initially successfully treated pharmacologically and immediate PCI < 2 hr, and in patients initially successfully treated with pharmacological therapy and with delayed PCI (12-72 h).

METHODS

451 reperfused STEMI patients, aged 18 to 75 years, class I-II Killip, with an acceptable echocardiographic window and admitted within 12 hs of the onset of symptoms were randomized into two groups. All patients had to have successful reperfusion, to receive the combination of a standard tirofiban infusion or abciximab plus half dose rtPA. Thereafter, patients were sub-grouped as follows:group 1 (immediate PCI) patients had PCI within 2 h; and group 2 (delayed PCI) patients in which PCI was performed after 12 hs and within 72 hs.

RESULTS

The 225 reperfused (immediate-PCI) and 226 reperfused (delayed-PCI) patients (time from randomization to PCI 165 +/- 37 min in immediate PCI versus 45.1 +/- 20.2 h in delayed PCI group) showed similar results in ejection fraction, CK release and patency of the IRA. In addition, the delayed PCI group showed a significant reduction in ischemic events, restenosis and bleedings (P = 0.005, 0.01, 0.01 respectively) and significant reduced angiographic evidence of thrombus formation in the infarction-related artery (IRA) (p = 0.001).

CONCLUSION

Our data suggest the safety and possible use of delayed facilitated PCI in patients with STEMI, and that delayed PCI in patients treated with combined lytic and IIb/IIIa inhibitors appears to be as effective and possibly superior (reduced ischemic events and repeat PCI) as immediate PCI. The patients in this study were successfully reperfused, with TIMI-3 flow and our data may not apply to patients with TIMI 0-2 flow. This strategy could allow transferring the reperfused patients and performing PCI after hours < 72 hours and not immediately, thereby reducing the number of urgent PCI and costs, obtaining similar results, but mostly causing less discomfort to the patient. Our results had to be interpreted with caution, because current guidelines do not recommend the combined therapy, but suggest further studies. The study was aimed to investigate the outcomes in patients initially successfully treated pharmacologically and immediate PCI < 2 h, and in patients initially successfully treated with pharmacological therapy and delayed PCI (12-72 h). All patients had to have successful reperfusion, to receive the combination of a standard abciximab or tirofiban infusion plus half dose rtPA. Similar results were observed in both groups. Delayed PCI group showed a significant lower incidence in restenosis (0.01), minor bleedings (0.005), ischemic events (0.01) and a reduced angiographic evidence of thrombus formation in IRA (0.001). Our data suggest the safety and possible use of delayed facilitated PCI in patients with STEMI. Our results had to be interpreted with caution, because current guidelines do not recommend the combined therapy, but suggest further studies.

Immediate versus delayed facilitated percutaneous coronary intervention: a pilot study

The study was aimed to investigate the outcomes in patients initially successfully treated pharmacologically and immediate PCI <2 hours, and in patients initially successfully treated with pharmacological therapy and delayed PCI (12-72 hours). All patients had to have successful reperfusion, to receive the combination of a standard abciximab infusion plus half dose rtPA. Similar results were observed in both groups. Delayed PCI group showed a favorable trend in restenosis and bleedings (ns) and a significant reduced angiographic evidence of thrombus formation in IRA. Our very preliminary data suggest the safety and possible use of delayed facilitated PCI in patients with STEMI. The studied patients have successful reperfusion and TIMI-3 flow and our data may not apply to patients with TIMI 0-2 flow.