Canadian Spontaneous Coronary Artery Dissection Cohort Study: 3-Year Outcomes.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-aged women. OBJECTIVES: We aim to define the long-term natural history of SCAD. METHODS: We performed a multicenter, prospective, observational study of patients with nonatherosclerotic SCAD presenting acutely from 22 North American centers. We recorded baseline demographics, in-hospital characteristics, precipitating and predisposing conditions, angiographic features (adjudicated), in-hospital and 3-year major adverse cardiovascular events (MACE). Cox regression multivariable analysis was performed. RESULTS: We prospectively enrolled 750 consecutive patients with SCAD from June 2014 to June 2018. Mean age was 51.7 ± 10.5 years, 88.5% were women (55.0% postmenopausal); 31.3% presented with ST-segment elevation myocardial infarction, and 68.3% with non-ST-segment elevation myocardial infarction. Precipitating emotional stressor was reported in 50.3%, and physical stressor in 28.9%. Predisposing conditions included fibromuscular dysplasia in 42.9% (56.4% in those with complete screening), peripartum state 4.5%, and genetic disorders 1.6%. Most patients were treated conservatively (84.3%); 14.1% underwent percutaneous coronary intervention (PCI), 0.7% coronary artery bypass graft. At 3.0-year median follow-up, mortality was 0.8%, recurrent MI 9.9% (extension of previous SCAD 3.5%, de novo recurrent SCAD 2.4%, iatrogenic dissection 1.9%), with overall MACE 14.0%. Presence of genetic disorders, peripartum SCAD, and extracoronary fibromuscular dysplasia were independent predictors of 3-year MACE. Patients who underwent PCI at index hospitalization had similar postdischarge MACE compared with no PCI. At 3 years, 80.0% remained on aspirin and 73.5% on beta-blockade. CONCLUSIONS: Long-term mortality and de novo recurrent SCAD was low in our contemporary large SCAD cohort that included low revascularization rate and high use of beta-blockade and aspirin. Genetic disorders, extracoronary fibromuscular dysplasia, and peripartum SCAD were independent predictors of long-term MACE.

Morphine and clinical outcomes in patients with ST segment elevation myocardial infarction treated with fibrinolytic and antiplatelet therapy: Insights from the TREAT trial.

BACKGROUND: Morphine is commonly used to relieve pain, anxiety and dyspnea in STEMI but it lowers blood pressure and delays the activity of oral antiplatelet agents. The impact of morphine on clinical outcomes remains unknown. This analysis was performed to determine if morphine use was associated with increased risk of adverse clinical events among STEMI patients treated with fibrinolytic therapy and clopidogrel or ticagrelor. METHODS: In the Ticagrelor in Patients with ST Elevation Myocardial Infarction Treated with Pharmacological Thrombolysis (TREAT) study, 3799 STEMI patients treated with fibrinolysis were randomized to receive clopidogrel or ticagrelor. Morphine use was left to the discretion of the treating physicians. In this pre-specified analysis, we evaluated clinical outcomes based on the use and timing of morphine administration. Outcomes were stratified by randomized treatment group. Multivariable analysis was performed using Inverse Probability Treatment Weighting (IPTW) weighting. RESULTS: Morphine was used in 53% of patients. After adjustment using IPTW weighting, morphine use was associated with higher hazard of reinfarction at 7 days (HR 4.9, P = .0006) and 30 days (HR 1.7, P = .04), and lower hazard of major bleeding (HR 0.37, P = .006). There was no significant difference in mortality at any time point. CONCLUSIONS: Among patients with STEMI treated with fibrinolytic therapy, morphine use was associated with a higher risk of early reinfarction and a lower risk of major bleeding but no difference in mortality. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02298088.

Use and outcomes of dual antiplatelet therapy for acute coronary syndrome in patients with chronic kidney disease: insights from the Canadian Observational Antiplatelet Study (COAPT).

Chronic kidney disease (CKD) increases the risk of adverse outcomes in acute coronary syndrome (ACS). The optimal regimen of dual antiplatelet therapy (DAPT) post-percutaneous coronary intervention (PCI) in CKD poses a challenge due to the increased bleeding and clotting tendencies, particularly since patients with CKD were underrepresented in randomized controlled trials. We examined the practice patterns of DAPT prescription stratified by the presence of CKD. The multicentre prospective Canadian Observational Antiplatelet Study (COAPT) enrolled patients with ACS between December 2011 and May 2013. The present study is a subgroup analysis comparing type and duration of DAPT and associated outcomes among patients with and without CKD (eGFR < 60 ml/min/1.73 m2, calculated by CKD-EPI). Patients with CKD (275/1921, 14.3%) were prescribed prasugrel/ticagrelor less (18.5% vs 25.8%, p = 0.01) and had a shorter duration of DAPT therapy versus patients without CKD (median 382 vs 402 days, p = 0.003). CKD was associated with major adverse cardiovascular events (MACE) at 12 months (p < 0.001) but not bleeding when compared to patients without CKD. CKD was associated with MACE in both patients on prasugrel/ticagrelor (p = 0.017) and those on clopidogrel (p < 0.001) (p for heterogeneity = 0.70). CKD was associated with increased bleeding only among patients receiving prasugrel/ticagrelor (p = 0.007), but not among those receiving clopidogrel (p = 0.64) (p for heterogeneity = 0.036). Patients with CKD had a shorter DAPT duration and were less frequently prescribed potent P2Y12 inhibitors than patients without CKD. Overall, compared with patients without CKD, patients with CKD had higher rates of MACE and similar bleeding rates. However, among those prescribed more potent P2Y12 inhibitors, CKD was associated with more bleeding than those without CKD. Further studies are needed to better define the benefit/risk evaluation, and establish a more tailored and evidence-based DAPT regimen for this high-risk patient group.

The COVID-19 Pandemic and Coronary Angiography for ST-Elevation Myocardial Infarction, Use of Mechanical Support, and Mechanical Complications in Canada: A Canadian Association of Interventional Cardiology National Survey.

BACKGROUND: As a result of the COVID-19 pandemic first wave, reductions in ST-elevation myocardial infarction (STEMI) invasive care, ranging from 23% to 76%, have been reported from various countries. Whether this change had any impact on coronary angiography (CA) volume or on mechanical support device use for STEMI and post-STEMI mechanical complications in Canada is unknown. METHODS: We administered a Canada-wide survey to all cardiac catheterization laboratory directors, seeking the volume of CA use for STEMI performed during the period from March 1 2020 to May 31, 2020 (pandemic period), and during 2 control periods (March 1, 2019 to May 31, 2019 and March 1, 2018 to May 31, 2018). The number of left ventricular support devices used, as well as the number of ventricular septal defects and papillary muscle rupture cases diagnosed, was also recorded. We also assessed whether the number of COVID-19 cases recorded in each province was associated with STEMI-related CA volume. RESULTS: A total of 41 of 42 Canadian catheterization laboratories (98%) provided data. There was a modest but statistically significant 16% reduction (incidence rate ratio [IRR] 0.84; 95% confidence interval 0.80-0.87) in CA for STEMI during the first wave of the pandemic, compared to control periods. IRR was not associated with provincial COVID-19 caseload. We observed a 26% reduction (IRR 0.74; 95% confidence interval 0.61-0.89) in the use of intra-aortic balloon pump use for STEMI. Use of an Impella pump and mechanical complications from STEMI were exceedingly rare. CONCLUSIONS: We observed a modest 16% decrease in use of CA for STEMI during the pandemic first wave in Canada, lower than the level reported in other countries. Provincial COVID-19 caseload did not influence this reduction.

INTRODUCTION: Après la première vague de la pandémie de COVID-19, de nombreux pays ont déclaré une réduction de 23 % à 76 % des soins invasifs de l'infarctus du myocarde avec élévation du segment ST (STEMI). On ignore si ce changement a entraîné des répercussions sur le volume d'angiographies coronariennes (AC) ou sur l'utilisation des dispositifs d'assistance mécanique lors de STEMI et des complications mécaniques post-STEMI au Canada. MÉTHODES: Nous avons réalisé un sondage pancanadien auprès de tous les directeurs de laboratoire de cathétérisme cardiaque pour obtenir le volume d'utilisation des AC lors des STEMI réalisées durant la période du 1er mars 2020 au 31 mai 2020 (période de pandémie) et durant 2 périodes témoins (1er mars 2019 au 31 mai 2019 et 1er mars 2018 au 31 mai 2018). Le nombre de dispositifs d'assistance ventriculaire gauche utilisés et le nombre de cas de communications interventriculaires et de ruptures du muscle papillaire diagnostiqués ont également été enregistrés. Nous avons aussi évalué si le nombre de cas de COVID-19 enregistrés dans chaque province était associé au volume d'AC liées aux STEMI. RÉSULTATS: Au total, 41 des 42 laboratoires canadiens de cathétérisme (98 %) ont fourni des données. Lors de la comparaison de la première vague de la pandémie aux périodes témoins, nous avons noté une réduction modeste, mais significative, sur le plan statistique de 16 % (ratio du taux d'incidence [RTI] 0,84; intervalle de confiance à 95 % 0,80-0,87) des AC lors de STEMI. Le RTI n'était pas associé au nombre provincial de cas de COVID-19. Nous avons observé une réduction de 26 % (RTI 0,74; intervalle de confiance à 95 % 0,61-0,89) de l'utilisation de pompes à ballonnet intra-aortique lors de STEMI. L'utilisation d'une pompe Impella et les complications mécaniques après les STEMI étaient extrêmement rares. CONCLUSIONS: Nous avons observé une diminution modeste de 16 % de l'utilisation des AC lors de STEMI durant la première vague de la pandémie au Canada, soit une diminution plus faible que ce que les autres pays ont signalé. Le nombre provincial de cas de COVID-19 n'a pas influencé cette réduction.

Screening for Fabry Disease in patients with unexplained left ventricular hypertrophy.

Fabry Disease (FD) is a systemic disorder that can result in cardiovascular, renal, and neurovascular disease leading to reduced life expectancy. FD should be considered in the differential of all patients with unexplained left ventricular hypertrophy (LVH). We therefore performed a prospective screening study in Edmonton and Hong Kong using Dried Blood Spot (DBS) testing on patients with undiagnosed LVH. Participants found to have unexplained LVH on echocardiography were invited to participate and subsequently subjected to DBS testing. DBS testing was used to measure α-galactosidase (α-GAL) enzyme activity and for mutation analysis of the α-galactosidase (GLA) gene, both of which are required to make a diagnosis of FD. DBS testing was performed as a screening tool on patients (n = 266) in Edmonton and Hong Kong, allowing for detection of five patients with FD (2% prevalence of FD) and one patient with hydroxychloroquine-induced phenocopy. Left ventricular mass index (LVMI) by GLA genotype showed a higher LVMI in patients with IVS4 + 919G > A mutations compared to those without the mutation. Two patients were initiated on ERT and hydroxychloroquine was discontinued in the patient with a phenocopy of FD. Overall, we detected FD in 2% of our screening cohort using DBS testing as an effective and easy to administer screening tool in patients with unexplained LVH. Utilizing DBS testing to screen for FD in patients with otherwise undiagnosed LVH is clinically important due to the availability of effective therapies and the value of cascade screening in extended families.

Pharmacoinvasive Strategy Versus Primary Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction in Clinical Practice: Insights From the Vital Heart Response Registry.

BACKGROUND: Recent clinical trial data support a pharmacoinvasive strategy as an alternative to primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction. We evaluated whether this is true in a real-world prehospital ST-segment elevation myocardial infarction network using ECG assessment of reperfusion coupled with clinical outcomes within 1 year. METHODS: Of the 5583 ST-segment elevation myocardial infarction patients in the Alberta Vital Heart Response Program (Cohort 1 [2006-2011]: n=3593; Cohort 2 [2013-2016]: n=1990), we studied 3287 patients who received a pharmacoinvasive strategy with tenecteplase (April 2013: half-dose tenecteplase was employed in prehospital patients ≥75 years) or pPCI. ECGs were analyzed within a core laboratory; sum ST-segment deviation resolution ≥50% was defined as successful reperfusion. The primary composite was all-cause death, congestive heart failure, cardiogenic shock, and recurrent myocardial infarction within 1 year. RESULTS: The pharmacoinvasive approach was administered in 1805 patients (54.9%), (493 [27.3%] underwent rescue/urgent percutaneous coronary intervention and 1312 [72.7%] had scheduled angiography); pPCI was performed in 1482 patients (45.1%). There was greater ST-segment resolution post-catheterization/percutaneous coronary intervention with a pharmacoinvasive strategy versus pPCI (75.8% versus 64.3%, IP-weighted odds ratio, 1.59; 95% CI, 1.33-1.90; P<0.001). The primary composite was significantly lower with a pharmacoinvasive approach (16.3% versus 23.1%, IP-weighted hazard ratio, 0.84; 95% CI, 0.72-0.99; P=0.033). Major bleeding and intracranial hemorrhage were similar between a pharmacoinvasive strategy and pPCI (7.6% versus 7.5%, P=0.867; 0.6% versus 0.6%; P=0.841, respectively). In the 82 patients ≥75 years with a prehospital pharmacoinvasive strategy, similar ST-segment resolution and rescue rates were observed with full-dose versus half-dose tenecteplase (75.8% versus 88.9%, P=0.259; 31.0% versus 29.2%, P=0.867) with no difference in the primary composite (31.0% versus 25.0%, P=0.585). CONCLUSIONS: In this large Canadian ST-segment elevation myocardial infarction registry, a pharmacoinvasive strategy was associated with improved ST-segment resolution and enhanced outcomes within 1 year compared with pPCI. Our findings support the application of a selective pharmacoinvasive reperfusion strategy when delay to pPCI exists.

Canadian spontaneous coronary artery dissection cohort study: in-hospital and 30-day outcomes.

AIMS: Spontaneous coronary artery dissection (SCAD) was underdiagnosed and poorly understood for decades. It is increasingly recognized as an important cause of myocardial infarction (MI) in women. We aimed to assess the natural history of SCAD, which has not been adequately explored. METHODS AND RESULTS: We performed a multicentre, prospective, observational study of patients with non-atherosclerotic SCAD presenting acutely from 22 centres in North America. Institutional ethics approval and patient consents were obtained. We recorded baseline demographics, in-hospital characteristics, precipitating/predisposing conditions, angiographic features (assessed by core laboratory), in-hospital major adverse events (MAE), and 30-day major adverse cardiovascular events (MACE). We prospectively enrolled 750 SCAD patients from June 2014 to June 2018. Mean age was 51.8 ± 10.2 years, 88.5% were women (55.0% postmenopausal), 87.7% were Caucasian, and 33.9% had no cardiac risk factors. Emotional stress was reported in 50.3%, and physical stress in 28.9% (9.8% lifting >50 pounds). Predisposing conditions included fibromuscular dysplasia 31.1% (45.2% had no/incomplete screening), systemic inflammatory diseases 4.7%, peripartum 4.5%, and connective tissue disorders 3.6%. Most were treated conservatively (84.3%), but 14.1% underwent percutaneous coronary intervention and 0.7% coronary artery bypass surgery. In-hospital composite MAE was 8.8%; peripartum SCAD patients had higher in-hospital MAE (20.6% vs. 8.2%, P = 0.023). Overall 30-day MACE was 8.8%. Peripartum SCAD and connective tissue disease were independent predictors of 30-day MACE. CONCLUSION: Spontaneous coronary artery dissection predominantly affects women and presents with MI. Despite majority of patients being treated conservatively, survival was good. However, significant cardiovascular complications occurred within 30 days. Long-term follow-up and further investigations on management are warranted.

Outcomes of medically managed patients with myocardial infarction.

AIMS: The purpose of this study was to compare outcomes associated with medical management of ST-elevation myocardial infarction and non-ST-elevation myocardial infarction patients presenting to hospitals with and without onsite catheterization facilities. METHODS: All patients (n=25,921) with ST-elevation myocardial infarction (n=10,563) or non-ST-elevation myocardial infarction (n=15,358) in Alberta, Canada between April 2010-March 2016 were categorized according to availability of catheterization facilities at the hospital they presented to and their management strategy (medically managed without coronary angiography or medically managed after coronary angiography). RESULTS: Overall, 51% presented to hospitals without catheterization facilities; and 34% were managed medically (18% without coronary angiography, and 16% after coronary angiography). Rates of medical management were higher at hospitals without versus those with catheterization facilities (43% vs. 24%, p<0.01). However, both the rate of presentation to hospitals without catheterization facilities (70% non-ST-elevation myocardial infarction, 24% ST-elevation myocardial infarction, p<0.01) and medical management (45% non-ST-elevation myocardial infarction, 18% ST-elevation myocardial infarction, p<0.01) differed by myocardial infarction type. The lack of catheterization facilities at the presenting hospital had no association with in-hospital mortality in patients medically managed without coronary angiography, but was associated with a lower risk of mortality among patients medically managed after coronary angiography. However, the latter benefit was restricted to non-ST-elevation myocardial infarction patients only (adjusted hazard ratio 0.43, 95% confidence interval: 0.25-0.76). CONCLUSION: The availability of catheterization facilities at the hospital at which non-ST-elevation myocardial infarction and ST-elevation myocardial infarction patients presented influenced their likelihood of being medically managed, but was not associated with adverse short- or long-term mortality outcomes.

Population-level incidence and outcomes of myocardial infarction with non-obstructive coronary arteries (MINOCA): Insights from the Alberta contemporary acute coronary syndrome patients invasive treatment strategies (COAPT) study.

BACKGROUND: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a known clinical conundrum with limited investigation. Using a large population-based cohort, we examined the incidence, demographic profile, use of evidence-based medicines (EBM) and clinical outcomes of MINOCA patients. METHODS: Patients hospitalized with a primary diagnosis of MI who underwent coronary angiography between 01/04/2002 and 31/03/2014 in Alberta, Canada, were included in the study. Comparisons were made between patients with MINOCA versus obstructive coronary disease (OCD). The primary composite endpoint was 1-year all-cause death or re-MI. RESULTS: Of 35,928 patients hospitalized with MI, 2092 (5.8%) had MINOCA. In-hospital mortality rate was 0.8% among MINOCA, and 2.7% among patients with OCD (p < 0.0001). At 6 months, cardiovascular EBM rates were significantly lower among MINOCA patients compared to OCD patients. One-year death/re-MI rate was 5.3% in MINOCA and 8.9% in patients with OCD (adjusted hazard ratio (AHR) 0.75, 95% confidence interval (CI) 0.62-0.92, p < 0.0001). Five-year mortality rates were 10.9% in MINOCA and 16.0% in patients with OCD. Upon further stratification, 770 (36.8%) of MINOCA patients had no angiographic evidence of CAD (i.e. normal angiograms). EBM rates were even lower among these patients. One-year death/re-MI rate among these patients was 3.9% as compared to 6.1% among MINOCA patients with stenosis <50% (AHR 0.68, 95% CI 0.44-1.07, p = 0.028). CONCLUSIONS: The population-level incidence of MINOCA is approximately 5%. Despite their apparently benign anatomic findings, efforts must be made to improve secondary prevention strategies to reduce the burden of long-term adverse outcomes in this population.

Relationships Between Baseline Q Waves, Time From Symptom Onset, and Clinical Outcomes in ST-Segment-Elevation Myocardial Infarction Patients: Insights From the Vital Heart Response Registry.

BACKGROUND: Using a comprehensive ST-segment-elevation myocardial infarction registry, we evaluated the relationships of baseline Q waves, time from symptom onset, and reperfusion strategy with in-hospital clinical outcomes. METHODS AND RESULTS: Consecutive ST-segment-elevation myocardial infarction patients from a defined health region were classified by the presence of baseline Q waves and additionally into primary percutaneous coronary intervention, fibrinolysis, or no reperfusion. ECGs were collected at baseline, after reperfusion, and analyzed for the presence of Q waves using Selvester criteria. Among 2290 ST-segment-elevation myocardial infarction patients, 36.9% had Q waves on their baseline ECG. Patients with Q waves were older (median age, 59 versus 57), were more often male (82.0% versus 75.4%), had higher heart rate (80 versus 72), had higher Global Registry of Acute Coronary Events risk score (129 versus 127), and were with longer time to reperfusion (42 minutes longer). They had higher composite end points (16.3% versus 10.0%), consistent across times from symptom onset to presentation (15.4% versus 9.9% ≤3 hours; 18.5% versus 8.9% >3 to ≤6 hours; 15.9% versus 11.3% >6 hours; Q and no Q, respectively). Baseline Q waves, but not time to reperfusion, were associated with an increased odds of the in-hospital composite end point of death, congestive heart failure, cardiogenic shock, and reinfarction (adjusted odds ratio, 1.65; 95% confidence interval, 1.18-2.30; P=0.003). Type of reperfusion did not modify the association of baseline Q waves and in-hospital outcomes (P interaction=0.918). CONCLUSIONS: The presence of baseline Q waves, rather than time to treatment, was significantly associated with adverse in-hospital events in real-world patients, regardless of reperfusion strategy used.

Hospital variation in treatment and outcomes in acute coronary syndromes: Insights from the Alberta Contemporary Acute Coronary Syndrome Patients Invasive Treatment Strategies (COAPT) study.

BACKGROUND: We examined variation in hospital treatment and its relationship to clinical outcome in a large population-based cohort of ACS patients within a single payer-government funded health care system. METHODS: Patients hospitalized in 106 hospitals in Alberta, Canada with a primary diagnosis of ACS were included (July 1, 2010-March 31, 2013) with comparisons made across the three cardiac catheterization-capable hospitals (Sites A-C). Cox proportional-hazard regression models were used to examine the multivariable-adjusted association between site and 1-year death or repeat cardiovascular (CV) hospitalization (primary endpoint). RESULTS: Of 14,155 patients, 1938 (13.7%) were admitted to a community hospital without transfer to an invasive hospital (10.7% in-hospital death). The remaining were admitted (n=4514, 36.9%) or transferred (n=7703, 63.1%) to an invasive hospital (A:5480; B:3621; C:3116) where 11,247 (92.1%) underwent catheterization. Comorbidities and angiographic disease burden differed across sites. Variation in 30-day revascularization (PCI: 71.3%, 72.0%, 68.7%, p<0.001; CABG: 6.2%, 6.4%, 9.3%, p<0.001) and drug-eluting stent use for PCI (24.3%, 54.6%, 50.5%, p<0.001) were observed. After adjustment for patient demographics and comorbidities, variation in rates of 1-year death or CV hospitalization was observed among those with 30-day revascularization (p(interaction)<0.001; B versus A: HR 0.78, 95%CI 0.66-0.91; C versus A: HR 0.77, 95%CI 0.65-0.91; B versus C: HR 1.01, 95%CI 0.84-1.21). CONCLUSIONS: Despite a government funded health system, we have shown variation in hospital treatment exists. Following adjustment hospital site was associated with differences in clinical outcome within 1year. Hence, further efforts may be warranted to help address potential disparities in ACS care.

Structural Heart Disease Intervention: The Canadian Landscape.

Cardiovascular disease encompasses coronary artery disease and valvular heart disease, and the prevalence of both increases with age. Over the past decade, the landscape of interventional cardiology has evolved to encompass a new set of percutaneous procedures outside the coronary tree, including transcatheter aortic valve implantation, transcatheter mitral valve repair, and left atrial appendage occlusion. These interventions have sparked a new discipline within interventional cardiology referred to as structural heart disease (SHD) intervention. The access to and numbers of such procedures performed in Canada is currently unknown. This "first of its kind" survey of structural interventions provides insight into the landscape of SHD intervention in Canada and the challenges faced by cardiologists to deliver this important care.

Longitudinal treatment patterns with ADP receptor inhibitors after myocardial infarction: Insights from the Canadian Observational AntiPlatelet sTudy.

BACKGROUND: After myocardial infarction (MI) treated with percutaneous coronary intervention (PCI), guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and an ADP receptor inhibitor (ADPri) for at least 1year. However, whether real-world Canadian practice patterns reflect this recommendation is unknown. METHODS: We studied 2175 MI patients treated with PCI and discharged from 26 Canadian hospitals between 12/2011 and 05/2013 in the Canadian Observational Antiplatelet sTudy (COAPT). Hierarchical Cox proportional hazard regression modeling was used to determine baseline demographic and clinical factors associated with duration of ADPri therapy post-discharge. RESULTS: At index-hospitalization discharge, 1597 (73%) patients were treated with clopidogrel, 220 (10%) with prasugrel, and 358 (17%) with ticagrelor. ADPri was discontinued prior to 1year in 474 (21.8%) patients; discontinuation rates were lowest for patients discharged on prasugrel (17.7%), compared with clopidogrel (22.5%) or ticagrelor (21.0%), (log rank test, p=0.03). In addition to regional variability, factors associated with shorter ADPri duration included older age, low body weight, Killip III/IV heart failure, atrial fibrillation, ticagrelor on discharge, and bare metal stent use, while longer ADPri duration was associated with history of prior MI. CONCLUSIONS: One in five PCI-treated MI patients did not complete Canadian guideline-recommended 1-year course of ADPri treatment. Premature ADPri discontinuation was most strongly associated with factors that increase the risk of bleeding. Further study is required to assess the clinical implications of premature ADPri discontinuation on patient outcomes.

Evaluating clinical reason and rationale for not delivering reperfusion therapy in ST elevation myocardial infarction patients: Insights from a comprehensive cohort.

BACKGROUND: In ST elevation myocardial infarction (STEMI), reperfusion therapy is lifesaving but is not delivered in approximately one quarter of patients. To address this care gap, we reviewed all STEMI patients that did not receive reperfusion to identify patient characteristics, in-hospital outcomes and the clinical reason or rationale for withholding reperfusion therapy. METHODS: A prospective chart review identified a consecutive cohort of STEMI patients over one-year within a defined health care region with independent data abstraction. Subsequently a trained nurse completed retrospective chart review and categorized patients by rationale for failure to receive reperfusion. RESULTS: Of 745 STEMI patients, 181 (24.3%) did not receive reperfusion. Compared to those receiving reperfusion, they were older (67.5 vs. 58.0years, p=0.001) with more comorbidities and higher in-hospital mortality (15.5% vs. 3.5% p=<0.0001). After excluding 35 patients (unavailable data) there were 146 STEMI patients for qualitative determination. Patient delay greater than 12hours from symptom onset accounted for the majority of patients (56/146, 38.4%). In 19.9% (29/146), conservative medical management with documented rationale occurred. Following angiography, primary PCI was attempted but was unsuccessful or no culprit lesion identified in 19.2% (28/146). The diagnosis of STEMI was missed or no rationale for failure to deliver therapy identified in 8.2% (12/146). Death prior to planned reperfusion occurred in 8 (8/146, 5.5%). CONCLUSIONS: Legitimate rationale exists for the majority of STEMI patients not receiving reperfusion. Ultimately, only 1.6% (12/745) of consecutive STEMI patients failed to receive reperfusion without documented rationale or due to missed diagnosis.

Providing Rapid Out of Hospital Acute Cardiovascular Treatment 4 (PROACT-4).

BACKGROUND: Whether prehospital point-of-care (POC) troponin further accelerates the time to diagnosis in patients with chest pain (CP) is unknown. We conducted a randomized trial of POC-Troponin testing in the ambulance. METHODS AND RESULTS: Patients with chest pain presenting by ambulance were randomized to usual care (UC) or POC-Troponin; ST-elevation myocardial infarction patients or those with noncardiovascular symptoms were excluded. Pre-hospital high-sensitivity troponin was analyzed on a POC device and available to the paramedic and emergency department (ED) staff. The final diagnosis was centrally adjudicated. The primary endpoint was time from first medical contact to discharge from ED or admission to hospital. We randomized 601 patients in 19 months; 296 to UC and 305 to POC-Troponin. After ambulance arrival, the first troponin was available in 38 minutes in POC-Troponin and 139 minutes in UC. In POC-Troponin, the troponin was >0.01 ng/mL in 17.4% and >0.03 ng/mL in 9.8%. Patients spent a median of 9.0 hours from first medical contact to final disposition, and 165 (27.4%) were admitted to the hospital. The primary endpoint was shorter in patients randomized to POC-Troponin (median 8.8 hours [6.2-10.8] compared to UC (median 9.1 hours [6.7-11.2]; P=0.05). There was no difference in the secondary endpoint of repeat ED visits, hospitalizations, or death in the next 30 days. CONCLUSIONS: In this broad population of patients with CP, ambulance POC-Troponin accelerated the time to final disposition. Enhanced and more cost-effective early ED discharge of the majority of patients with CP calling 911 is an unrealized opportunity. CLINICAL TRIAL REGISTRATION: URL: https://www.ClinicalTrials.gov/. Unique identifier: NCT01634425.

Treatment choices in elderly patients with ST: elevation myocardial infarction-insights from the Vital Heart Response registry.

BACKGROUND: Management of elderly patients with ST elevation myocardial infarction (STEMI) is challenging and they are under-represented in trials. Accordingly, we analysed reperfusion strategies and their effectiveness in patients with STEMI ≥75 years compared to <75 years within a comprehensive inclusive registry. METHODS: Consecutive patients with STEMI admitted to hospital and tracked within a regional registry (2006-2011) were analysed comparing reperfusion strategy (primary percutaneous coronary intervention (PPCI), fibrinolysis and no reperfusion) between patients ≥75 vs <75 years old as well as across the reperfusion strategies in those ≥75 years. RESULTS: There were 3588 patients with STEMI with 646 (18%) ≥75 years old. Elderly patients were more likely female (46.9% vs 18.4%) and had more prior: angina (28.2% vs 17.2%), myocardial infarction (MI; 22.8% vs 13.9%), hypertension (67.6% vs 44.2%), heart failure (2.3% vs 0.3%) and atrial fibrillation (2.2% vs 0.5%) (all p<0.001). The reperfusion strategy for patients ≥75 vs <75: PPCI 45.3% vs 41.2%, fibrinolysis 24.8% vs 45.7%, and no reperfusion 29.9% vs 13.1% (p<0.001). Time from symptoms to first medical contact (median, 93 vs 78 min p=0.008) and PPCI (median, 166 vs 136 min (p<0.001) were longer for ≥75 years. In those ≥75 years outcomes by reperfusion (PPCI, fibrinolysis and none) were: in-hospital death 13.3%, 9.4% and 19.7% (p=0.018), and composite of death, recurrent-MI, cardiogenic shock and congestive heart failure 28%, 20% and 33.2% (p=0.022). CONCLUSIONS: Elderly patients have more comorbidities, worst in-hospital clinical outcomes and are less likely to receive reperfusion. Acknowledging physician selection of the reperfusion strategy; outcomes appear favourable in the elderly receiving fibrinolysis.

Providing Rapid Out of Hospital Acute Cardiovascular Treatment 3 (PROACT-3).

BACKGROUND: The outcomes of acute cardiovascular symptom presentations are potentially modifiable with the use of biomarkers to accelerate accurate diagnosis. This randomized trial tested troponin and B-type natriuretic peptide before hospital guidance in patients with acute cardiovascular symptoms. METHODS: Patients with either chest pain or shortness of breath were randomized to usual care or biomarkers analyzed using a point-of-care device in the ambulance. The primary end point was time to final disposition (discharge from the emergency department or admission to hospital). The trial was stopped prematurely because of less than expected enrollment of patients of interest and no difference in the primary end point. RESULTS: We randomized 491 patients; 480 formed the final cohort. Patients were 49% male; median age 70 years; 42% had previous acute coronary syndrome; and 28% diabetes. The B-type natriuretic peptide level before hospital arrival was ≥ 100 pg/mL in 36.4%. Troponin was > 0.03 ng/mL in 13.4%; 3.6% had troponin > 0.1 ng/mL. After adjudication, 16% had acute coronary syndrome, 6.5% acute heart failure, 3.3% angina, and 74.2% another diagnosis. The primary end point was 9.2 (interquartile range, 7.3-11.1) hours in the biomarker group and 8.8 (interquartile range, 6.3-12.1) hours in the usual care group (P = 0.6). None died in the ambulance or in the emergency department: all-cause 30-day mortality was 2.1% (usual care) and 1.7% (biomarker). CONCLUSIONS: To our knowledge, this is the first randomized trial of biomarkers before hospital arrival to guide emergency management of suspected acute cardiovascular disease which showed no benefit and was terminated early because of futility. The results have important implications for the use of biomarkers in emergency management of heart disease and for the design of future randomized trials on this important topic.

Bridging the gap for nonmetropolitan STEMI patients through implementation of a pharmacoinvasive reperfusion strategy.

BACKGROUND: Timely primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in ST-elevation myocardial infarction (STEMI). However, universal access is limited outside metropolitan centres and portends worse outcomes for rural patients. This study evaluates the outcomes of STEMI patients treated in a metropolitan and nonmetroplitan setting within Vital Heart Response, an integrated reperfusion program developed to reduce reperfusion delay in Central and Northern Alberta. METHODS: From October 2006 to March 2011, data on consecutive STEMI patients was prospectively recorded. Clinical characteristics, in-hospital management, and outcomes grouped by site of presentation are described. RESULTS: There were 1990 metropolitan and 1602 nonmetropolitan STEMI patients. Metropolitan were older (62.7 vs 60.4 years; P < 0.001) and had more: angina (21.2% vs 16.5%; P < 0.001), dyslipidemia (45.3% vs 39.6%; P = 0.001), and hypertension (49.9% vs 46.6%; P = 0.047). The reperfusion strategy for metropolitan and nonmetropolitan: primary PCI (57.4% vs 22.9%; P < 0.001), fibrinolysis (26.3% vs 61.2%; P < 0.001), and no reperfusion (16.3% vs 15.9%; P = 0.855). First medical contact to reperfusion was delayed in nonmetropolitan with fibrinolysis and PCI, 8 and 125 minutes. A rescue PCI or coronary angiography within 24 hours was completed in 41.4% and 46.2%, respectively. Nonmetropolitan patients had fewer deaths (4.1% vs 6.8%; P = 0.001) with no difference in the composite outcome (death, reinfraction, congestive heart failure, cardiogenic shock) (16.8% vs 15.1%; P = 0.161) or major bleeding (7.9% vs 8.0%; P = 0.951). CONCLUSIONS: Systematic application of a pharmacoinvasive strategy appears to be safe and effective for patients in whom a delay in mechanical reperfusion is anticipated.

Mode of hospital presentation in patients with non-ST-elevation myocardial infarction: implications for strategic management.

INTRODUCTION: Contemporary non-ST-elevation myocardial infarction-acute coronary syndrome guidelines emphasize early-risk stratification and optimizing therapy including an invasive strategy in high-risk patients. To assess the feasibility of initiating this strategy in the prehospital environment, we examined how such patients are transported to hospital, their risk profile, and the proportion potentially eligible for such a strategy. METHODS: Consecutive patients with ST-segment elevation myocardial infarction admitted in Edmonton were studied between September and November 2008 and divided according to their mode of transport to hospital: emergency medical services (EMS) versus self-presenting. Baseline characteristics, GRACE Risk Score, blinded core laboratory electrocardiogram analysis, cardiac biomarkers, in-hospital procedures, and outcomes were analyzed. RESULTS: Thirty-five percent (93/263) of patients presented via EMS and often to percutaneous coronary intervention hospitals, that is, 64.5% versus 44.1% (P = .0016). They were older (75 vs 62 years, P < .001), more often female (43% vs 28.1%, P < .001), diabetic (34.4% vs 22.9%, P = .045), and hypertensive (72.0% vs 57.1%, P = .017) and had higher GRACE Risk Scores (median 166 vs 130, P < .001). Electrocardiogram analysis revealed more baseline Q waves (38.8% vs 25.5%, P = .031) and ST depression ≥2 mm (P = .027) in EMS-transported patients. Fewer EMS patients underwent cardiac catheterization (60.2% vs 88.2%, P < .001), and a paradoxical relationship existed between catheterization rates and GRACE Risk Score in the total cohort (low-risk: 93.4% vs high-risk: 59.3%, P < .001). The composite of death/re-myocardial infarction/congestive heart failure/shock was greater in EMS patients (unadjusted odds ratio 3.96, 95% CI 1.80-8.69, P = .001); these differences were attenuated after GRACE Risk Score adjustment. CONCLUSION: Regional strategies using risk-based triage, early medical therapy, and timely triage to percutaneous coronary intervention centers represents an unrealized opportunity to enhance ST-segment elevation myocardial infarction care.

Suburban cardiac screening: improving access to specialist services within a primary care network.

This article evaluates a cardiac screening program by analyzing wait times and exploring associations between administratively tracked variables and confirmed cardiac diagnosis. The findings indicate that the wait times for specialist consultation are shorter than previously reported in Alberta and age and sex have the strongest associations with a confirmed cardiac diagnosis.