Canadian Cardiovascular Society/Canadian Cardiovascular Critical Care Society/Canadian Association of Interventional Cardiology Clinical Practice Update on Optimal Post Cardiac Arrest and Refractory Cardiac Arrest Patient Care

Survival to hospital discharge among patients with out-of-hospital cardiac arrest (OHCA) is low and important regional differences in treatment practices and survival have been described. Since the 2017 publication of the Canadian Cardiovascular Society's position statement on OHCA care, multiple randomized controlled trials have helped to better define optimal post cardiac arrest care. This working group provides updated guidance on the timing of cardiac catheterization in patients with ST-elevation and without ST-segment elevation, on a revised temperature control strategy targeting normothermia instead of hypothermia, blood pressure, oxygenation, and ventilation parameters, and on the treatment of rhythmic and periodic electroencephalography patterns in patients with a resuscitated OHCA. In addition, prehospital trials have helped craft new expert opinions on antiarrhythmic strategies (amiodarone or lidocaine) and outline the potential role for double sequential defibrillation in patients with refractory cardiac arrest when equipment and training is available. Finally, we advocate for regionalized OHCA care systems with admissions to a hospital capable of integrating their post OHCA care with comprehensive on-site cardiovascular services and provide guidance on the potential role of extracorporeal cardiopulmonary resuscitation in patients with refractory cardiac arrest. We believe that knowledge translation through national harmonization and adoption of contemporary best practices has the potential to improve survival and functional outcomes in the OHCA population.

Reperfusion in Patients With ST-Segment-Elevation Myocardial Infarction With Cardiogenic Shock and Prolonged Interhospital Transport Times

BACKGROUND

In patients with ST-segment-elevation myocardial infarction complicated by cardiogenic shock, primary percutaneous coronary intervention (pPCI) is the preferred revascularization option. Little is known about the efficacy and safety of a pharmacoinvasive approach for patients with cardiogenic shock presenting to a non-PCI hospital with prolonged interhospital transport times.

METHODS

In a retrospective analysis of geographically extensive ST-segment-elevation myocardial infarction network (2006-2021), 426 patients with cardiogenic shock and ST-segment-elevation myocardial infarction presented to a non-PCI-capable hospital and underwent reperfusion therapy (53.8% pharmacoinvasive and 46.2% pPCI). The primary clinical outcome was a composite of in-hospital mortality, renal failure requiring dialysis, cardiac arrest, or mechanical circulatory support, and the primary safety outcome was major bleeding defined as an intracranial hemorrhage or bleeding that required transfusion was compared in an inverse probability weighted model. The electrocardiographic reperfusion outcome of interest was the worst residual ST-segment-elevation.

RESULTS

Patients with pharmacoinvasive treatment had longer median interhospital transport (3 hours versus 1 hour) and shorter median symptom-onset-to-reperfusion (125 minute-to-needle versus 419 minute-to-balloon) times. ST-segment resolution ≥50% on the postfibrinolysis ECG was 56.6%. Postcatheterization, worst lead residual ST-segment-elevation <1 mm (57.3% versus 46.3%; P=0.01) was higher in the pharmacoinvasive compared with the pPCI cohort, but no differences were observed in the worst lead ST-segment-elevation resolution ≥50% (77.4% versus 81.8%; P=0.57). The primary clinical end point was lower in the pharmacoinvasive cohort (35.2% versus 57.0%; inverse probability weighted odds ratio, 0.44 [95% CI, 0.26-0.72]; P<0.01) compared with patients who received pPCI. An interaction between interhospital transfer time and reperfusion strategy with all-cause mortality was observed, favoring a pharmacoinvasive approach with transfer times >60 minutes. The incidence of the primary safety outcome was 10.1% in the pharmacoinvasive arm versus 18.7% in pPCI (adjusted odds ratio, 0.41 [95% CI, 0.14-1.09]; P=0.08).

CONCLUSIONS

In patients with ST-segment-elevation myocardial infarction presenting with cardiogenic shock and prolonged interhospital transport times, a pharmacoinvasive approach was associated with improved electrocardiographic reperfusion and a lower rate of death, dialysis, or mechanical circulatory support without an increase in major bleeding.

Simulation in cardiac critical care

Medical simulation is a broad topic but at its core is defined as any effort to realistically reproduce a clinical procedure, team, or situation. Its goal is to allow risk-free practice-until-perfect, and in doing so, augment performance, efficiency, and safety. In medicine, even complex clinical situations can be dissected into reproducible parts that may be repeated and mastered, and these iterative improvements can add up to major gains. With our modern cardiac intensive care units treating a growing number of medically complex patients, the need for well-trained personnel, streamlined care pathways, and quality teamwork is imperative for improved patient outcomes. Simulation is therefore a potentially life-saving tool relevant to anyone working in cardiac intensive care. Accordingly, we believe that simulation is a priority for cardiac intensive care, not just a luxury. We offer the following primer on simulation in the cardiac intensive care environment.

Demographics and risk factors that influence the prevalence of depression in patients attending cardiac rehabilitation

Depression has been associated with adverse outcomes in patients with cardiac disease. Data on its prevalence and the factors influencing it are limited in the cardiac rehabilitation program (CRP) setting. To elucidate the prevalence of and the factors that influence depression in patients attending CRP. Patients attending the CRP from 2003 to 2016 were included in the study. All patients had a Beck Depression Inventory-II (BDI-II) performed prior to commencement in CRP and were followed longitudinally. The BDI-II for the 4989 patients were as follows: 0 to 13 (normal) = 3623 (72%); 14 to 19 (mild depression) = 982 (20%); 20 to 28 (moderate depression) = 299 (6%); 29 to 63 (severe depression) = 85 (2%). The BDI-II (mean ± SEM) for males (mean age: 60.8 ± 0.1 years) and females (mean age: 63.4 ± 0.3 years, P < .001) were 7.0 ± 0.1 and 8.5 ± 0.2 (P < .001), respectively. Elevated BDI-II scores (14-63) were more common in type 1 (41.1%) and type 2 (30.5%) diabetics than nondiabetics (25.7%). Similarly, elevated scores were more common in smokers (36.1%) than never-smokers (24.7%). The BDI-II scores for Caucasians, South Asians, and East Asians were 7.3 ± 0.1, 8.0 ± 0.3, and 7.0 ± 0.3 respectively (P = .01 for CA vs SA by 1-way ANOVA and least significant difference test). The prevalence of depression is high in patients attending CRP affecting 28% of the population. BDI-II is a simple validated screening tool that can be applied to patients attending CRP. Diabetics, current smokers, and South Asians all had a higher prevalence of depression.

Differences in Clinical Measures and Outcomes in South Asians vs Caucasians Attending Cardiac Rehabilitation

Background

South Asians have a greater predisposition to cardiac events, compared to Caucasians. Although cardiac rehabilitation programs (CRPs) are known to improve outcomes, data are sparse regarding benefits acquired by South Asians vs Caucasians. The objective of the current study was to determine the outcomes of South Asian patients undergoing CRPs, compared to Caucasian patients.

Methods

This study compared baseline characteristics and outcomes in all patients attending a CRP in Edmonton, Canada with a proportionately large South Asian population.

Results

From 1998 to 2016, a total of 811 South Asians and 5406 Caucasians attended CRPs. Baseline characteristics revealed that there were more nonsmokers (73.4% vs 29.4%, P < 0.001), with a lower body mass index (26.8 ± 0.1 vs 29.6 ± 0.1, P < 0.001), but higher prevalence of diabetes (37.7% vs 20.5%, P < 0.001) in the South Asian population. Outcome measures revealed that South Asians spent less time in the CRP (6.9 weeks ± 0.1 vs 7.3 weeks ± 0.1, P < 0.001), attended the nutrition class less (36.2% vs 53.4%, P < 0.001), and had a lower 6-minute walk improvement (66.9 m vs 73.6 m, P < 0.001). Frequency of use of β-blockers (86.9% vs 86.1%, P > 0.05), antiplatelet agents (96.3% vs 97.1%, P > 0.05), angiotensin-converting enzyme inhibitors (79.9% vs 80.0%, P > 0.05), and cholesterol-lowering agents (91.4% vs 93.8%, P > 0.05) was not significantly different.

Conclusions

Although South Asians seem to be prescribed and use proven pharmacologic treatments to the same extent as Caucasians, they appeared to benefit less from CRPs. Given higher event rates in South Asians, consideration should be given to altering the delivery of CRPs to South Asians to improve their efficacy.

Plasma Exchange for Immune Checkpoint Inhibitor-Induced Myocarditis

Immune checkpoint inhibitor therapy has been shown to improve outcomes across many types of malignancies. However, immune checkpoint inhibitor has been associated with several immune-related adverse events including myocarditis. We describe the case of a 69-year-old man with fulminant myocarditis likely due to pembrolizumab therapy, complicated by biventricular failure with cardiogenic shock. Because of deterioration in hemodynamic status refractory to conventional immunosuppression, therapeutic plasma exchange was performed, resulting in a rapid reduction of serum pembrolizumab levels, and marked clinical, radiological, and biochemical improvement. To our knowledge, this is the first reported case on the successful use of plasma exchange for pembrolizumab-associated fulminant myocarditis.

Approach to Ventricular Arrhythmias in the Intensive Care Unit

Arrhythmias are commonly encountered in the intensive care unit as a primary admitting diagnosis or secondary to an acute illness. Appropriate identification and treatment of ventricular arrhythmias in this setting are particularly important to reduce morbidity and mortality. This review highlights the epidemiology, mechanisms, electrocardiographic features, and treatment of ventricular arrhythmias.

Variables Associated With Cardiac Surgical Waitlist Mortality From a Population-Based Cohort

BACKGROUND

Cardiac surgery waitlist recommendations, which were developed based on expert opinion, poorly predict preoperative mortality. Studies reporting risk factors for waitlist mortality have not evaluated the risks including nonadherence to waitlist benchmarks.

METHODS

In patients who underwent cardiac surgery or died on the waitlist between 2005 and 2015, we used a Fine and Gray competing risk model to identify independent predictors of waitlist mortality in 12,106 patients scheduled for urgent, semiurgent, or nonurgent surgery. The predictive variables were compared with Canadian Cardiovascular Society (CCS) waitlist recommendations using the Akaike information criterion.

RESULTS

A total of 101 (0.8%) patients died awaiting surgery. The median wait times and frequency waitlist deaths among emergent, urgent, semi-urgent, and nonurgent surgery were 0.6, 7.4, 69.0, 55.5 days (P < 0.001) and 6.3%, 0.8%, 0.3%, 0.6% (P < 0.001), respectively. Adherence to CCS waitlist recommendations was higher in patients who died on the waitlist (51.6% vs 70.8%, P = 0.001) and was not predictive of waitlist mortality (hazard ratio 1.48, 95% confidence interval 0.62-0.56). Independent predictors of waitlist mortality were age, aortic surgery, ejection fraction < 35%, urgent surgery, prior myocardial infarction, haemodynamic instability during cardiac catheterization, hypertension, and dyslipidemia. These variables were superior to current CCS guidelines (Akaike information criterion 1251 vs 1317, likelihood ratio test P < 0.001).

CONCLUSIONS

CCS waitlist recommendations were poorly predictive of waitlist mortality and the majority of waitlist deaths occur within recommended benchmarks. We identified variables associated with waitlist mortality with improved clinical performance. Our findings suggest a need to re-evaluate cardiac surgical triage criteria using evidence-based data.

Clinical and angiographic outcomes associated with surgical revascularization of angiographically borderline 50-69% coronary artery stenoses

OBJECTIVES

Coronary artery bypass grafting (CABG) improves outcomes in patients with multivessel coronary artery disease. Bypass of angiographically significant lesions ≥70% is recommended, yet little is known about the incidence/outcomes with bypasses of 50-69% angiographically borderline lesions (ABLs) without fractional flow reserve testing. The objective of this study was to investigate the incidence and outcomes of bypass of 50-69% ABLs.

METHODS

Between 2007 and 2013, 3195 patients underwent isolated first multivessel CABG. Patients with an isolated ABL of a major epicardial vessel were included. Outcomes of interest included time to all-cause mortality, and 30-day and 1-year mortality.

RESULTS

Among 350 patients with an ABL, 268 (76.6%) had the vessel containing the ABL bypassed, while 82 (23.4%) did not. The mean follow-up was 4.2 years. Patients with a bypassed ABL were older (66.1 vs 62.5 mean years, P = 0.006) but otherwise similar in sex, comorbidities, diabetes, ejection fraction and number of coronary stenoses. Cardiopulmonary bypass time was longer in patients with bypassed ABLs (104.2 vs 90.4 min, mean, P < 0.001). Unadjusted overall mortality until the end of follow-up was higher among patients with bypassed ABLs (11.6 vs 3.7%, P = 0.034). After multivariable adjustment, the association between ABL bypass and mortality was attenuated (hazard ratio 2.84, 95% confidence interval: 0.87-9.23, P = 0.080). No differences were observed in unadjusted 30-day (1.1 vs 0.0%, P = 0.336) or 1-year mortality (4.1 vs 0.0%, P = 0.062). Repeat revascularization rate of patients with bypassed ABLs was numerically higher (4.1 vs 0.0%, P = 0.107).

CONCLUSIONS

In an unselected cohort of patients with ABLs, bypass of borderline 50-69% lesions is frequently performed and not associated with improved long-term survival. Our findings suggest that the routine surgical revascularization of 50-69% ABLs may not be warranted.

Screening for aortic aneurysms in patients with coronary artery disease: should it be done?

Aneurysmal dilation of the aorta is a clinically silent disease that often presents first with a catastrophic event. As a result, several clinician societies and organizations have recommended screening to detect aneurysms before they rupture. Although screening may reduce mortality, the implementation of screening has been poor. Cardiologists are uniquely positioned to improve this gap as they handle patients with typical risk factors for aneurysmal diseases of the aorta and can endorse and implement screening in a high-risk population. The following article attempts to concisely give a navigational tool to the cardiovascular specialist for her/his role in the diagnosis and management of thoracic and abdominal aortic aneurysms, citing evidence as well as stating opinions on how to improve outcomes in this unique patient population.

A 19-year study on pacemaker-related infections: a claim for using postoperative antibiotics

BACKGROUND

Although the incidence of pacemaker-related infection (PMINF) is low, it necessitates removal of the pacing system. There is currently no consensus on antibiotics during implantation.

METHODS

A prospective database on patients undergoing pacemaker surgery from 1991 to 2009 was reviewed to determine factors associated with PMINF. Specifically, three eras of antibiotic use were compared to elucidate the effect of antibiotics on PMINF: no antibiotics, perioperative antibiotics, and peri- plus postoperative antibiotics.

RESULTS

There were 3,253 procedures with PMINF identified in 46 (1.4%) patients. Over 19 years, PMINF incidence fell from 3.6% (no antibiotics) to 2.9% (perioperative antibiotics), to 0.4% (peri- plus postoperative antibiotics). On univariate analysis, the following were associated with PMINF: nonuse of postoperative antibiotics (3.0% vs 0.4%, P < 0.001), year of implant (P < 0.001), repeat procedures (2.3% vs 1%, P = 0.006), nonuse of perioperative antibiotics (3.6% vs 1.3%, P = 0.027). With postoperative antibiotics, rates were significantly reduced in new implants (1/1,289 = 0.1% vs 22/967 = 2.3%, P < 0.001) and repeat procedures (7/692 = 1.0% vs 16/305 = 5.2%, P < 0.001). On multivariate analysis, the following were significant (standardized coefficients denote relative importance): postoperative antibiotics (0.776), repeat procedures (0.508), year of implant (0.142), perioperative antibiotics (0.088).

CONCLUSIONS

The PMINF rate is reduced significantly by perioperative antibiotics with a further significant reduction with postoperative antibiotics. However, the reduction in PMINF rate could be a result of changes in practice in the different time eras. This study suggests consideration of perioperative followed by postoperative antibiotics to minimize pacemaker infections.