Lillian Ding

Improved survival associated with pre-hospital triage strategy in a large regional ST-segment elevation myocardial infarction program.

OBJECTIVES This study sought to compare the 1-year survival of patients diagnosed with ST-segment elevation myocardial infarction (STEMI) and transferred via pre-hospital triage strategy for primary percutaneous coronary intervention (PCI) with those transferred via inter-hospital transfer within a large suburban region in Canada. BACKGROUND Primary angioplasty is the preferred therapy for STEMI if it is done within 90 min of door-to-balloon time by an experienced team in a high-volume center. METHODS Patients identified to have STEMI on the ambulances equipped with electrocardiography bypassed the local hospitals and were sent directly to the PCI center, whereas other patients that were picked up by ambulances without electrocardiographic equipment were transported to the local hospitals where the diagnosis of STEMI was made and were re-routed to the PCI center. Patient demographic data, clinical presentation, procedural data, in-hospital course, and vital statistics were prospectively recorded in a provincial cardiac registry. RESULTS A total of 167 patients were brought into the PCI center via pre-hospital triage strategy, and 427 patients were brought in via inter-hospital transfer during a 2-year study period. Baseline demographic data, infarct location, cardiovascular history, and hemodynamic status were similar between the 2 groups. When compared with the inter-hospital transfer group, a significantly higher proportion of pre-hospital triaged patients achieved the 90-min door-to-balloon time benchmark (80.4% vs. 8.7%, p < 0.001) and post-procedural Thrombolysis In Myocardial Infarction flow grade 3 after the emergency procedure (97.6% vs. 91.4%, p = 0.02). In addition, the pre-hospital triage strategy was associated with a significantly lower 30-day (5.4% vs. 13.3%, p = 0.006) and 1-year (6.6% vs. 17.5%, p = 0.019) mortality. Pre-hospital triage was an independent predictor for survival at 1 year (hazard ratio: 0.37, 95% confidence interval: 0.18 to 0.75, p = 0.006). CONCLUSIONS Pre-hospital triage strategy was associated with improved survival rate in patients undergoing primary PCI in a regional STEMI program.

Percutaneous Coronary Intervention and 30-Day Mortality: The British Columbia PCI Risk Score

Objectives: To construct a calculator to assess the risk of 30‐day mortality following PCI. Background: Predictors of 30‐day mortality are commonly used to aid management decisions for cardiac surgical patients. There is a need for an equivalent risk‐score for 30‐day mortality for percutaneous coronary intervention (PCI) as many patients are suitable for both procedures. Methods: The British Columbia Cardiac Registry (BCCR) is a population‐based registry that collects information on all PCI procedures performed in British Columbia (BC). We used data from the BCCR to identify risk factors for mortality in PCI patients and construct a calculator that predicts 30‐day mortality. Results: Patients (total n = 32,899) were divided into a training set (n = 26,350, PCI between 2000 and 2004) and validation set (n = 6,549, PCI in 2005). Univariate predictors of mortality were identified. Multivariable logistic regression analysis was performed on the training set to develop a statistical model for prediction of 30‐day mortality. This model was tested in the validation set. Variables that were objective and available before PCI were included in the final risk score calculator. The 30‐day mortality for the overall population was 1.5% (n = 500). Area under the ROC curve was 90.2% for the training set and 91.1% for the validation set indicating that the model also performed well in this group. Conclusions: We describe a large, contemporary cohort of patients undergoing PCI with complete follow‐up for 30‐day mortality. A robust, validated model of 30‐day mortality after PCI was used to construct a risk calculator, the BC‐PCI risk score, which can be accessed at www.bcpci.org.

Long-term outcomes following drug-eluting stents versus bare metal stents for primary percutaneous coronary intervention: A real-world analysis of 11,181 patients from the british columbia cardiac registry.

Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare metal stents (BMS). Their use in ST‐elevation myocardial infarction (STEMI) is debated, owing to concerns about stent thrombosis. There are limited real‐world data comparing DES versus BMS in STEMI. We conducted an observational analysis in this setting and rigorously adjusted for treatment selection bias.

Intra-Aortic Balloon Pump Counterpulsation during Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction and Cardiogenic Shock: Insights from the British Columbia Cardiac Registry

Background Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with significant morbidity and mortality. In the primary percutaneous coronary intervention (PPCI) era, randomized trials have not shown a survival benefit with intra-aortic balloon pump (IABP) therapy. This differs to observational data which show a detrimental effect, potentially reflecting bias and confounding. Without robust and valid risk adjustment, findings from non-randomized studies may remain biased. Methods We compared long-term mortality following IABP therapy in patients with cardiogenic shock undergoing PPCI during 2008–2013 from the British Columbia Cardiac Registry. We addressed measured and unmeasured confounding using propensity score and instrumental variable methods. Results A total of 12,105 patients with STEMI were treated with PPCI during the study period. Of these, 700 patients (5.8%) had cardiogenic shock. Of the patients with cardiogenic shock, 255 patients (36%) received IABP therapy. Multivariable analyses identified IABP therapy to be associated with increased mortality up to 3 years (HR = 1.67, 95% CI:1.20–2.67, p<0.001). This association was lost in propensity-matched analyses (HR = 1.23, 95% CI: 0.84–1.80, p = 0.288). When addressing measured and unmeasured confounders, instrumental variable analyses demonstrated that IABP therapy was not associated with mortality at 3 years (Δ = 16.7%, 95% CI: -12.7%, 46.1%, p = 0.281). Subgroup analyses demonstrated IABP was associated with increased mortality in non-diabetics; patients not undergoing multivessel intervention; patients without renal disease and patients not having received prior thrombolysis. Conclusions In this observational analysis of patients with STEMI and cardiogenic shock, when adjusting for confounding, IABP therapy had a neutral effect with no association with long-term mortality. These findings differ to previously reported observational studies, but are in keeping with randomized trial data.

Long-term Outcomes of Multiple Arterial Coronary Artery Bypass Grafting: A Population-Based Study of Patients in British Columbia, Canada

Importance Although the long-term survival advantage of multiple arterial grafting (MAG) vs the standard use of left internal thoracic artery (LITA) supplemented by saphenous vein grafts (LITA+SVG) has been demonstrated in several observational studies, to our knowledge its safety and other long-term clinical benefits in a large, population-based cohort are unknown. Objective To compare the safety and long-term outcomes of MAG vs LITA+SVG among overall and selected subgroups of patients. Design, Setting, and Participants In this population-based observational study, we included 20 076 adult patients with triple-vessel or left-main disease who underwent primary isolated coronary artery bypass grafting (MAG, n = 5580; LITA+SVG, n = 14 496) in the province of British Columbia, Canada, from January 2000 to December 2014, with follow-up to December 2015. We performed propensity-score analyses by weighting and matching and multivariable Cox regression to minimize treatment selection bias. Exposures Multiple arterial grafting or LITA+SVG. Main Outcomes and Measures Mortality, repeated revascularization, myocardial infarction, heart failure, and stroke. Results Of 5580 participants who underwent MAG, 586 (11%) were women and the mean (SD) age was 60 (8.7) years. Of 14 496 participants who underwent LITA+SVG, 2803 (19%) were women and the mean (SD) age was 68 (8.9) years. The median (interquartile range) follow-up time was 9.1 (5.1-12.6) years and 8.1 (4.5-11.7) years for the groups receiving MAG and LITA+SVG, respectively. Compared with LITA+SVG, MAG was associated with reduced mortality rates (hazard ratio [HR], 0.79; 95% CI, 0.72-0.87) and repeated revascularization rates (HR, 0.74; 95% CI, 0.66-0.84) in 15-year follow-up and reduced incidences of myocardial infarction (HR, 0.63; 95% CI, 0.47-0.85) and heart failure (HR, 0.79; 95% CI, 0.64-0.98) in 7-year follow-up. The long-term benefits were coherent by all 3 statistical methods and persisted among patient subgroups with diabetes, obesity, moderately impaired ejection fraction, chronic obstructive pulmonary disease, peripheral vascular disease, or renal disease. Multiple arterial grafting was not associated with increased morbidity or mortality rates at 30 days overall or within patient subgroups. Conclusions and Relevance Compared with LITA+SVG, MAG is associated with reduced mortality, repeated revascularization, myocardial infarction, and heart failure among patients with multivessel disease who are undergoing coronary artery bypass grafting without increased mortality or other adverse events at 30 days. The long-term benefits consistently observed across multiple outcomes and subgroups support the consideration of MAG for a broader spectrum of patients who are undergoing coronary artery bypass grafting in routine practice.

Long-term complications, reoperations and survival following cardioverter-defibrillator implant

Objective Implantable cardioverter-defibrillators (ICDs) reduce risk of death in select populations, but are also associated with harms. We aimed to characterise long-term complications and reoperation rate. Methods We assessed the rate, cumulative incidence and predictors of long-term reoperation and survival using a prospective, multicentre registry serving British Columbia in Canada, a universal single payer healthcare system with 4.5 million residents. 3410 patients (mean 63.3 years, 81.7% male) with new primary (n=1854) or secondary prevention (n=1556) ICD implant from 2003 to 2012 were followed for a median of 34 months (single chamber n=1069, dual chamber n=1905, biventricular n=436). Independent predictors of adverse outcomes were defined using Cox regression models. Results The overall reoperation rate was 12.0% per patient-year, and less for single vs dual vs biventricular ICDs (9.1% vs 12.5% vs 17.8% per patient-year, respectively). The Kaplan-Meier complication estimates (excluding generator end of life) at 1, 3 and 5 years were respectively: single chamber 10.2%, 16.2% and 21.6%; dual 11.7%, 19.1% and 27.4% and biventricular 15.9%, 22.2% and 24.7%. Cardiac resynchronisation therapy had the highest rate of early lead complications, but lower long-term need for upgrade. Device complexity, age and atrial fibrillation were key determinants of complications. Overall mortality at 1, 3 and 5 years was 5.4%, 17.4% and 32.7%, respectively. In younger patients, observed 5-year survival approached the expected survival in the general population (relative survival ratio=0.96 (0.90–0.98)). With increasing age, observed survival steadily declined relative to expected. Conclusions In a prospective registry capturing all procedures, complication and reoperation rates following de novo ICD implantation were high. Shared decision making must carefully consider these factors.

Embolic protection device use and its association with procedural safety and long-term outcomes following saphenous vein graft intervention: An analysis from the British Columbia Cardiac registry

Embolic protection devices (EPDs) have been designed and introduced to reduce distal embolization and peri‐procedural myocardial infarction during saphenous vein graft (SVG) intervention. Current guidelines give a class I recommendation to EPD use during SVG intervention when technically feasible. However, the routine use of these devices has recently been debated.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for emergency cardiac support

Purpose: Veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) may provide benefit to patients in refractory cardiac arrest and cardiogenic shock. We aim to summarize our centers 6‐year experience with resuscitative VA‐ECMO. Materials and methods: A retrospective medical record review (April 2009 to 2015) was performed on consecutive non‐cardiotomy patients who were managed with VA‐ECMO due to refractory in‐ or out‐of‐hospital cardiac (IHCA/OHCA) arrest (E‐CPR) or refractory cardiogenic shock (E‐CS) with or without preceding cardiac arrest. Our primary outcome was survival to hospital discharge and good neurological status (Cerebral Performance Category 1–2). Results: There were a total of 22 patients who met inclusion criteria of whom 9 received E‐CPR (8 IHCA, 1 OHCA) and 13 received E‐CS. The median age for E‐CPR patients was 52 [IQR 45, 58] years, and 54 [IQR 38, 64] years for E‐CS patients. Cardiac arrest duration was 70.33 (SD 39.56) min for the E‐CPR patients, and 24.67 (SD 26.73) min for the 9 patients treated with E‐CS who had previously arrested. Initial cardiac arrest rhythms were pulseless electrical activity (39%), ventricular fibrillation (33%), or ventricular tachycardia (28%). A total of 18/22 patients were successfully weaned from VA‐ECMO (78%); 16 patients survived to hospital discharge (73%) with 15 in good neurological condition. Conclusion: The initiation of VA‐ECMO at our center for treatment of refractory cardiac arrest and cardiogenic shock yielded a high proportion of survivors and favorable neurological outcomes. HighlightsMean duration from start of CPR to initiation of VA‐ECMO was 103.73 min (±98.41).Successful weaning from VA‐ECMO in 78% of patientsSurvival rate with good neurological condition (CPC 1‐2) was 67%) for E‐CPR, 69% for E‐CS and 68% overall

A score to estimate 30-day mortality after intensive care admission after cardiac surgery

Objective: Several risk‐scoring systems have been developed to predict surgical mortality and complications in cardiac surgical patients, but none of the current systems include factors related to the intraoperative period. The purpose of this study was to develop a score that incorporates both preoperative and intraoperative factors so that it could be used for patients admitted to a cardiac surgical intensive care unit (ICU) immediately after surgery. Method: Preoperative and intraoperative data from 30,350 patients in four hospitals were used to build a multiple logistic regression model estimating 30‐day mortality after cardiac surgery. Sixty percent of the patients were used as a derivation group and forty percent as a validation group. Results: Mortality occurred in 2.6% of patients (n = 790). Preoperative factors identified in the model were age, female sex, emergency status, pulmonary hypertension, peripheral vascular disease, renal dysfunction, diabetes, peptic ulcer disease, history of alcohol abuse, and refusal of blood products. Intraoperative risk factors included the need for an intra‐aortic balloon pump, ventricular assist device or extracorporeal membrane oxygenation leaving the operating room, presence of any intraoperative complication reported by the surgeon, the use of inotropes, high‐dose vasopressors, red blood cell transfusion, and cardiopulmonary bypass time. When used after surgery at ICU admission, the model had C‐statistics of 0.86 in both derivation and validation sets to estimate the 30‐day mortality. Conclusions: Preoperative and intraoperative variables can be used on admission to a cardiac surgical ICU to estimate 30‐day mortality. The score could be used for risk stratification after cardiac surgery and evaluation of performance of cardiac surgical ICUs.

Prognostic Significance of Polymer Coatings in Zotarolimus-Eluting Stents

Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic drugs. Whether they influence outcomes for contemporary DES is unknown. The evolution of polymer coatings for zotarolimus-eluting stents (ZES) provides a natural experiment that facilitates such analysis. The Resolute ZES (R-ZES) uses the same antirestenotic drug as the Endeavor ZES (E-ZES) but has a more biocompatible polymer with enhanced drug release kinetics. However, there are limited data on the real-world comparative efficacy of R-ZES and the preceding E-ZES. Thus, we analyzed 17,643 patients who received either E-ZES or R-ZES from 2008 to 2014 from the British Columbia Cardiac Registry. A total of 9,869 patients (56%) received E-ZES and 7,774 patients (44%) received R-ZES. Compared with E-ZES, R-ZES was associated with lower 2-year mortality (4.1% vs 6.4%, p <0.001) and 2-year target vessel revascularization (TVR; 6.8% vs 10.7%, p <0.001). R-ZES use was an independent predictor of lower mortality rate and TVR. This was confirmed in propensity-matched analyses for 2-year mortality (hazard ratio [HR] 0.59, 95% CI 0.49 to 0.71, p <0.001) and 2-year TVR (HR 0.86, 95% CI 0.75 to 0.98, p = 0.032). Instrumental variable analyses demonstrated R-ZES to be associated with lower 2-year mortality (Δ = -2.2%, 95% CI -4.3% to -0.2%, p = 0.032) and 2-year TVR (Δ = -3.3% to 95% CI -6.1% to -0.7%, p = 0.015). Acknowledging the limitations of observational analyses, this study has shown that R-ZES was associated with lower long-term TVR and mortality. These data are reassuring for the newer R-ZES and demonstrate how polymer coatings may influence the clinical performance of DES with wider implications for future DES development and design.