Abstract
Background: Invasive cardiac care is the preferred method of treatment for patients with acute coronary syndromes (ACS) complicated by cardiogenic shock (CS). In Nova Scotia, invasive cardiac care is only available in Halifax at the Queen Elizabeth II Health Sciences Centre (QEII-HSC). Methods: All consecutive patients diagnosed with ACS and CS in 2009-2013 in Nova Scotia were included. Data were obtained from the clinical database of Cardiovascular Health Nova Scotia. The primary outcome was in-hospital mortality. Results: A total of 418 patients with ACS and CS were admitted to the hospital. Access to invasive care was limited to 309 (73.9%) of these patients. For those who presented elsewhere in the province, 64.2% were transferred to the QEII-HSC. The mortality rate among the 309 patients with access to invasive care was significantly lower than that among the 109 patients who did not have access (41.7% vs 83.5%; P < 0.0001). Unadjusted mortality was lowest among patients undergoing primary percutaneous coronary intervention (33.1%). After adjustment for clinical differences, access to cardiac catheterization remained an independent predictor of survival (odds ratio, 0.2; 95% confidence interval, 0.11-0.36). Heat map analysis revealed that access was lowest in regions furthest from Halifax. Conclusions: ACS complicated by CS has a high mortality rate. We demonstrate that access to health care centres offering cardiac catheterization is independently associated with survival, and public health initiatives that improve access should be considered. Patients presenting furthest from Halifax were the least likely to be transferred, suggesting that geography remains an important barrier to livesaving care.
| Original language | English |
|---|---|
| Pages (from-to) | 202-208 |
| Number of pages | 7 |
| Journal | Canadian Journal of Cardiology |
| Volume | 34 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 2018 |
Bibliographical note
Funding Information:This research was supported by a summer studentship with funding provided by the Dalhousie Medical Research Foundation (DMRF) Leo Alexander Summer Studentship.
Funding Information:
This study is an analysis of all patients admitted to a hospital in Nova Scotia with ACS and concomitant CS between January 1, 2009 and December 31, 2013, the 5-year period after publication of the 2008 Cardiovascular Health Nova Scotia ACS management guidelines. Patient data were collected from the clinical registry of Cardiovascular Health Nova Scotia (formerly called the ICONS Database). The Cardiovascular Health Nova Scotia registry contains detailed clinical information for all patients admitted to Nova Scotia hospitals with ACS and heart failure. Data regarding a wide variety of clinical parameters are collected by a group of specially trained and experienced abstractors. These abstractors have achieved at least a 95% accuracy rate for data abstraction. We were provided with deidentified clinical information on all consecutive patients in our target population. Each patient was assigned a unique study identification number by Cardiovascular Health Nova Scotia. For the purposes of this study, relevant clinical information was retrieved pertaining to patients with a recorded admission date between January 1, 2009 and December 31, 2013. Inclusion criteria were a diagnosis of ACS with CS either on admission or at discharge, according to the attending physician or as noted in the patient's records during the hospital stay. Exclusion criteria were patients < 18 years of age or those with any condition having a clear contraindication to the administration of thrombolytic agents, such as major trauma. ACS was defined as any ST-elevation myocardial infarction (STEMI) or non–ST-elevation myocardial infarction (NSTEMI). STEMI was defined either by electrocardiographic criteria, a patient who underwent lysis, or a patient who received primary PCI. NSTEMI was defined according to a discharge diagnosis of AMI without ST-elevation. CS was defined as an admitting or discharge diagnosis of CS by the attending physician or any diagnosis of CS occurring during the hospital stay and noted in the patient's record, combined with the appropriate clinical picture as previously described. 10 The incidence of AMI and CS per 10,000 population during the 5-year study period was evaluated based on the hospital of admission and data from the 2013 Health Profile Census Data 12 and was further broken down to assess event rates at the level of what were, at the time, 9 separate district health authorities (DHA). The Cardiovascular Health Nova Scotia Registry does in fact track all patients with ACS, not just those with CS. Our decision to study a population of patients with ACS and shock was largely motivated by our previous study methodology and the desire to be able to compare findings between 2 eras in which major health care delivery changes had occurred. 10 Access to invasive cardiac care was defined as any patient admitted or transferred to the Queen Elizabeth II Health Sciences Centre (QEII-HSC) in Halifax, which is the only institution capable of providing invasive cardiac catheterization and cardiac surgery in Nova Scotia. Rate of transfer was calculated based on hospital of first presentation and transportation routes and resources organized between the DHAs. The primary outcome of interest was all-cause, in-hospital mortality (or 30 days) for our patients with ACS and CS. Other relevant outcomes included access to cardiac care at the QEII-HSC in Halifax, timeliness of cardiac catheterization for patients based on their time of symptom onset and first medical contact, and length of hospitalization. Patients were stratified into those with and those without access to invasive cardiac care. For both groups, data concerning prehospital and in-hospital parameters were recorded, as was basic patient demographic information. Approval for this study was granted by the Nova Scotia Health Authority Research Ethics Board (No. 100311), the Cardiovascular Health Nova Scotia Research Ethics Board, and the Department of Health and Wellness Data Access Committee (API No. 15-18). The analysis was performed with SAS, version 9.4 (SAS Institute, Cary, NC). Descriptive statistics included an independent Student t test, Wilcoxon rank sum test, χ 2 test, or Fisher exact test as appropriate for continuous and discrete variables. Statistical significance was defined as P < 0.05. The independent predictors of in-hospital mortality were identified by logistic regression. The clinically relevant variables included patient demographics (age, sex), previous history of heart disease (previous MI or intervention), additional organ failure (renal insufficiency), intervention (administration of thrombolytic agents), and access to invasive cardiac care. Our multivariable model used a backward selection approach to sequentially eliminate those variables not independently significant at P 75 years. Heat maps were produced using ArcMap software, version 10.3.1 (Esri, Redlands, CA) to provide visual representations of where patients with ACS and CS were most likely to present to a hospital throughout the province and which regions had the highest proportion of transfers to the QEII-HSC in Halifax. Data regarding hospital of first presentation were amalgamated based on the DHA and were expressed relative to the population of that DHA according to Statistics Canada 2013 census reports. 12 The proportion of patient transfers was expressed as the quotient of patients transferred to the QEII-HSC given the total number of patients who presented to a hospital in that DHA.
Publisher Copyright:
© 2017 Canadian Cardiovascular Society
ASJC Scopus Subject Areas
- Cardiology and Cardiovascular Medicine
