Collaborative Heart Attack Management Program (CHAMP): use of prehospital thrombolytics to improve timeliness of STEMI management in British Columbia.

Coronary artery disease is the second leading cause of death in Canada. Time to treatment in ST-elevation myocardial infarction (STEMI) is directly related to morbidity and mortality. Thrombolysis is the primary treatment for STEMI in many regions of Canada because of prolonged transport times to percutaneous coronary intervention-capable centres. To reduce time from first medical contact (FMC) to thrombolysis, some emergency medical services (EMS) systems have implemented prehospital thrombolysis (PHT). PHT is not a novel concept and has a strong evidence base showing reduced mortality.Here, we describe a quality improvement initiative to decrease time from FMC to thrombolysis using PHT and aim to describe our methods and challenges during implementation. We used a quality improvement framework to collaborate with hospitals, EMS, cardiology, emergency medicine and other stakeholders during implementation. We trained advanced care paramedics to administer thrombolysis in STEMI with remote cardiologist support and aimed to achieve a guideline-recommended median FMC to needle time of <30 min in 80% of patients.Overall, we reduced our median FMC to needle time by 70%. Our baseline patients undergoing in-hospital thrombolysis had a median time of 84 min (IQR 62-116 min), while patients after implementation of PHT had a median time of 25 min (IQR 23-39 min). Patients treated within the guideline-recommended time from FMC to needle of <30 min increased from 0% at baseline to 61% with PHT. Return on investment analysis showed $2.80 saved in acute care costs for every $1.00 spent on the intervention.While we did not achieve our goal of 80% compliance with FMC to needle time of <30 min, our results show that the intervention substantially reduced the FMC to needle time and overall cost. We plan to continue with ongoing implementation of PHT through expansion to other communities in our province.

Assessment of left ventricular filling pressure with Doppler velocities across the patent foramen ovale.

BACKGROUND: The utility of Doppler velocities across the patent foramen ovale (PFO) to estimate left ventricular (LV) filling pressure is not well known. METHODS: The best cut-off value of peak interatrial septal velocity across a transeptal puncture site measured by transesophageal echocardiography for estimating high mean left atrial (LA) pressure (≥ 15 mmHg) was determined in 17 patients. This cut-off value was subsequently applied to 67 patients with a PFO undergoing transthoracic echocardiography (TTE) for assessing the value of PFO velocity in determining LV filling pressure. RESULTS: The peak systolic interatrial septal velocities significantly correlated with directly measured mean LA pressures during transcatheter mitral valve procedure (r = 0.77, P < 0.001). The best cut-off value was 1.7 m/s for predicting high LA pressure (AUC 0.91; sensitivity 90%, specificity 86%). When this cut-off was applied to patients undergoing TTE, peak PFO velocity ≥ 1.7 m/s correlated with reduced e', higher E/e', and higher tricuspid regurgitation velocity (P < 0.01). LV filling pressure according to the 2016 diastolic guideline was compared with peak PFO velocity in 51 patients. Among patients with high filling pressure according to the guidelines (n = 20), peak PFO velocity ≥ 1.7 m/s was present in 60% of patients. In patients with normal filling pressure per the guidelines (n = 31), PFO velocity < 1.7 m/s was present 84%. Sensitivity and specificity were 75% and 92%, respectively, in patients with sinus rhythm, but were only 50% and 57%, respectively, among patients with atrial fibrillation. CONCLUSIONS: Doppler-derived peak PFO velocities could be valuable in the assessment of increased LV filling pressure using 1.7 m/s as the cut-off value.

Quantitative Three-Dimensional Echocardiographic Correlates of Optimal Mitral Regurgitation Reduction during Transcatheter Mitral Valve Repair.

BACKGROUND: Patient selection for transcatheter edge-to-edge mitral valve repair (TMVR) remains challenging because of heterogenous mitral valve pathology and highly variable anatomy. The aim of this study was to investigate whether quantitative three-dimensional (3D) transesophageal echocardiographic modeling parameters are associated with optimal mitral regurgitation (MR) reduction in patients undergoing TMVR. METHODS: Fifty-nine patients underwent 3D transesophageal echocardiography during TMVR. Volumetric data sets were retrospectively analyzed using mitral valve quantitative 3D modeling software (Mitral Valve Navigator). Optimal MR reduction was defined as less than moderate residual MR. Logistic regression was used to correlate 3D transesophageal echocardiographic quantitative data to procedural success. RESULTS: Thirty-five patients had primary MR, 24 had mixed or secondary MR, and all patients had grade ≥ 3/4 MR before the procedure. Optimal MR reduction was achieved in 40 of 59 patients (68%). Univariate correlates of optimal MR reduction in patients with primary MR were lower mitral leaflet tenting volume (P = .049) and lower tenting height (P = .025); tenting height < 3 mm and tenting volume < 0.7 mL were associated with increased likelihood of optimal MR reduction (92% vs 48% [P = .01] and 81% vs 47% [P = .03], respectively). In mixed or secondary MR, annular height ≥ 5.5 mm was associated with increased likelihood of optimal MR reduction (94% vs 38%; P = .03). During follow-up, redo TMVR or surgical mitral valve replacement occurred exclusively in patients with suboptimal anatomy defined by 3D transesophageal echocardiography (10% vs 0%, P = .045). CONCLUSIONS: Quantitative 3D echocardiographic data are associated with favorable response to TMVR and could help optimize patient selection.

Troubleshooting Cardiac Resynchronization Therapy in Nonresponders.

Heart failure (HF) is a critical health issue. Despite the advancements in pharmacotherapy, HF-related morbidity and mortality remains high. Cardiac resynchronization therapy (CRT) has been revolutionary in medically refractory, symptomatic HF patients with reduced ejection fraction and a prolonged, abnormal QRS complex. Although CRT affects electromechanical dys-synchrony resulting in favourable ventricular remodelling, improved functional capacity and clinical outcomes with fewer HF hospitalizations and better survival, the response to CRT is not uniform. A reported 20%-40% of patients, depending on the criteria used, are considered CRT nonresponders. Identifying a cause for nonresponse is challenging and often multifactorial and therefore requires a complete approach involving the entire patient journey. Effort to improve response includes careful consideration of selected patients, optimal therapy delivery, and comprehensive postimplantation care. Because of the prevalence of HF and generally poor prognosis, CRT provides an important treatment option, however, further research is needed to better understand reasons for CRT nonresponse and potential solutions.

Association Between Diabetes During Pregnancy and Peripartum Cardiomyopathy: A Population-Level Analysis of 309,825 Women.

BACKGROUND: Peripartum cardiomyopathy (PPCM) is a form of heart failure associated with pregnancy. The objectives of our study were to determine the incidence and outcomes (maternal and neonatal) of PPCM and its association with diabetes mellitus (DM) in a contemporary population-based cohort. METHODS: The cohort consisted of 309,825 women with a birth of at least 1 live newborn between January 01, 2005 and September 30, 2014, resulting in 469,150 birth events and 477,089 live newborns. A modified PPCM definition was used, allowing from 32 weeks' gestation and up to 6 months postpartum. Women were categorized according to DM status. RESULTS: A total of 194 PPCM birth events were identified, for an incidence rate of 1/2418 births. Women with PPCM were older, often primiparous, and more likely to have multiple gestations, pre-existing DM, and hypertensive disorders of pregnancy. Although the overall numbers were low, the incidence of PPCM was higher in pregnancies in women with pre-existing DM (1/613 birth events) and gestational DM (1/1751 birth events) vs those with neither (1/2550 birth events). Over a mean follow-up of 3.9 years, the mortality rate was higher in women affected by PPCM than in those who were not, with few deaths overall. Neonatal death was uncommon in the entire cohort but was numerically greater in the PPCM group. CONCLUSIONS: The incidence of PPCM in Alberta, Canada was approximately 1/2400 births and was modulated by the presence of DM in pregnancy. The relationship between DM status and PPCM may be confounded by other vascular risk factors, including hypertensive disorders of pregnancy. There were few maternal or neonatal deaths in the overall cohort, but they were numerically higher in the PPCM group.

Troponin rise in hospitalized patients with nonacute coronary syndrome: retrospective assessment of outcomes and predictors.

BACKGROUND: Cardiac troponin is elevated in several clinical settings apart from thrombotic acute coronary syndrome (ACS) and is associated with increased adverse events. It is not clear whether troponin elevation in type II myocardial infarction (MI) is associated with increased cardiovascular events. Our objectives were to identify the cause of mortality in type II MI and to attempt to establish the threshold range of cardiac troponin-I (cTnI) elevation as well as clinical factors associated with adverse outcomes in type II MI. METHODS: This retrospective cohort study included 245 patients presenting with a noncardiac primary diagnosis associated with cTnI elevation at a single centre from January 2003 to December 2011. Primary outcome was a composite of cardiovascular and noncardiovascular mortality. Secondary outcomes included subsequent stroke, ACS, and heart failure (HF). RESULTS: At 1 year, ACS occurred in 13 patients (5.3%), stroke was seen in 10 (4.1%) patients, and HF occurred in 19 (7.8%) patients. Overall 1-year mortality included 102 events (41.6%), with 10 cardiovascular deaths (9.8%), 65 noncardiovascular deaths (63.7%), and 27 (26.5%) deaths from unknown causes. In multivariable analysis, factors independently associated with increased overall 1-year mortality included cTnI elevation ≥ 4.63 µg/L (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.55-7.34; P = 0.002), age ≥ 70 years (OR, 2.44; 95% CI, 1.40-4.29; P = 0.002), and estimated glomerular filtration rate < 30 mL/min/1.73m(2) (OR, 2.40; 95% CI 1.31-4.40; P = 0.005). CONCLUSIONS: Unlike the published literature, our study includes a variety of both operative and nonoperative clinical settings associated with troponin elevation. We illustrate that although overall mortality is high after type II MI, the majority of mortality is caused by noncardiovascular events.

Cyclophosphamide-Induced Cardiomyopathy: A Case Report, Review, and Recommendations for Management.

Cyclophosphamide is increasingly used to treat various types of cancers and autoimmune conditions. Higher doses of this drug may produce significant cardiac toxicity, including fatal hemorrhagic myocarditis. In this review, we present a case of cyclophosphamide-induced cardiomyopathy requiring mechanical circulatory support. We also describe the pathophysiology, clinical manifestations, and risk factors for this important clinical entity and propose early detection and management strategies.