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Objective: To analyze outcomes and predictors of functional survival (personal care home admission and mortality) and hospital readmission in patients aged ≥80 years who underwent surgical aortic valve replacement (SAVR) in a Manitoba hospital., Methods: This was a retrospective cohort study of patients aged ≥80 years who underwent SAVR with or without coronary artery bypass grafting in Manitoba between 1995 and 2014. Data from the Manitoba Adult Cardiac Surgery database and the Manitoba Centre for Health Policy were used. Kaplan-Meier estimates of outcomes and Cox multivariate regression analysis of risk factors were performed. Survival was compared with that of age- and sex-matched life expectancy., Results: A total of 1872 patients were aged ≥50 years and 378 were aged ≥80 years, 55% of whom (n = 208) underwent concurrent coronary artery bypass grafting. Compared with younger patients, octogenarians had higher in-hospital mortality (8.5%; P <.001), longer median intensive care unit stay (47.2 hours; P <.001), and longer median in-hospital stay (13 days; P <.001). The median follow-up was 5.2 years. Functional survival was 82.4% at 1 year and 56.5% at 5 years, and freedom from hospital readmission was 61.5% at 1 year and 28.4% at 5 years. Survival approximated the age- and sex-matched life expectancy at 1 year (83.8%) and 5 years (60.8%). Preoperative atrial fibrillation, peripheral vascular disease, female sex, postoperative acute kidney injury, and blood transfusion were associated with adverse outcomes., Conclusions: In eligible octogenarians, SAVR has acceptable 1- and 5-year functional survival and hospital readmission rates, but significant perioperative mortality and morbidity., (Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Cold weather to 0°C has been implicated as a risk factor for ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks. The effect of more extreme cold weather on the risk of ventricular arrhythmias and ICD shocks is unknown. We sought to describe the relationship between extreme cold weather and the risk of ICD shocks. We retrospectively identified patients seen at the Pacemaker and Defibrillator Clinic at St. Boniface Hospital in Winnipeg, Manitoba, Canada between 2010 and 2015 with an ICD shock. We excluded multiple shocks occurring on the same day in a single patient. We collected weather data, and evaluated the relationship between ICD shocks and weather on the same day as the shock using Negative Binomial regression. Three hundred and sixty patients experienced a total of 1,355 shocks. When excluding multiple shocks occurring in a single patient on the same day, there were 756 unique shocks. The daily high (DH) was the strongest predictor of receiving an ICD shock. Compared with the warmest days (DH above 10°C), shocks were 25% more common on the coldest days (DH below -10°C), and 8% more common on cold days (DH between -10°C and 10°C). This linear trend was statistically significant, with a p-value of 0.04. In conclusion, we found an association between extreme cold weather and ICD shocks., (Copyright © 2017 Elsevier Inc. All rights reserved.)

This study aims to analyze survival, repeat hospitalization, and risk factors for surgically treated left-sided endocarditis. Retrospective review of all 166 (114 native and 52 prosthetic) patients operated between January 2004 and March 2015 was performed. Long-term survival and repeat hospitalization data for 134 of 166 patients were obtained via linked clinical databases with the Manitoba Centre for Health Policy. Kaplan-Meier estimates of survival and hospital readmission and Cox multivariable regression analysis of factors influencing outcomes were performed. Survival at 1 and 5 years was 91% and 80%, respectively, and major adverse prosthesis-related event repeat hospitalization rates were 12% and 21%, respectively. Repeat hospitalization because of endocarditis was 7% and 11% at 1 and 5 years, respectively. Survival and repeat hospitalization were similar for aortic and mitral valves. Survival after surgically treated endocarditis was similar to survival for age-, sex-, and valve-matched surgical valve replacements for noninfectious indications (P = 0.53). Viridans Streptococci was the most common organism in native valve endocarditis, and culture negative endocarditis was most common in prosthetic valves. Prosthetic valve endocarditis (P < 0.01) and preoperative renal dysfunction (P < 0.01) were risk factors for in-hospital mortality and major postoperative adverse events. Diabetes and renal dysfunction were associated with poor long-term survival, functional survival, and repeat hospitalization. This analysis suggests that surgery remains a very effective tool in management of these complex patients in terms of survival and major adverse prosthesis-related event repeat hospitalization., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Peripartum cardiomyopathy (PPCM) is a heterogeneous condition characterized by heart failure and left ventricular dysfunction (left ventricular ejection fraction [LVEF] < 45%) in the absence of an alternative cause and a previous diagnosis of cardiomyopathy. The Aboriginal population (Inuit, First Nations, Metis) of Canada often has barriers to health care, which can lead to delays in diagnosis and treatment. Our objectives are to describe PPCM in a Canadian population, and to determine if Canadian Aboriginal women have worse clinical outcomes than non-Aboriginal women., Methods: A retrospective study was performed at a single tertiary care centre, between 2008 and 2014. Demographic characteristics, symptoms at presentation, medical history, discharge medications, blood work, echocardiographic parameters, and follow-up information were collected., Results: A total of 177 women were screened, and 23 were included in the study (52% were Aboriginal). Aboriginal women were found to have higher rates of gravidity and parity, and higher incidence of tobacco smoking than non-Aboriginal women, and were more likely to be discharged with diuretic medications. At diagnosis, Aboriginal women were more likely to have a lower LVEF (20% [interquartile range (IQR), 15%-23%] vs 40% [IQR, 30%-42%]; P = 0.02) and a more dilated left ventricle (left ventricular end-diastolic diameter, 64 mm [IQR, 57-74 mm] vs 54 mm [IQR, 50-57mm]; P < 0.01). Recovery rate, defined as LVEF > 50%, was similar (46% in Aboriginal patients and 60% in non-Aboriginal patients)., Conclusions: Our findings support that Aboriginal women with PPCM are more likely to present with lower LVEF and a more dilated left ventricle, as well, require more symptomatic management. To our knowledge, this is the first description and contrast of PPCM between Aboriginal and non-Aboriginal Canadians., (Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Introduction: Acute kidney injury (AKI) is a potentially fatal complication of cardiac surgery. The inability to predict cardiac surgery-associated AKI is a major barrier to prevention and early treatment. Current clinical risk models for the prediction of cardiac surgery-associated AKI are insufficient, particularly in patients with preexisting kidney dysfunction., Methods: To identify intraoperative variables that might improve the performance of a validated clinical risk score (Cleveland Clinic Score, CCS) for the prediction of cardiac surgery-associated AKI, we conducted a prospective cohort study in 289 consecutive elective cardiac surgery patients at a tertiary care center. We compared the area under the receiver operator characteristic curve (AUC) of a base model including only the CCS with models containing additional selected intraoperative variables including mean arterial pressure, hematocrit, duration of procedure, blood transfusions, and fluid balance. AKI was defined by the Kidney Disease Improving Global Outcomes 2012 criteria., Results: The CCS alone gave an AUC of 0.72 (95% confidence interval, 0.62-0.82) for postoperative AKI. Nadir intraoperative hematocrit was the only variable that improved AUC for postoperative AKI when added to the CCS (AUC = 0.78; 95% confidence interval, 0.70-0.87; P  = 0.002). In the subcohort of patients without preexisting chronic kidney disease (n = 214), where the CCS underperformed (AUC, 0.60 [0.43-0.76]), the improvement with the addition of nadir hematocrit was more marked (AUC, 0.74 [0.62-0.86]). Other variables did not improve discrimination., Discussion: Nadir intraoperative hematocrit is useful in improving discrimination of clinical risk scores for AKI, and may provide a target for intervention.

Background: The efficacy of erythropoietin-stimulating agents (ESAs) for improving health-related quality of life (HRQOL) in anemia of chronic kidney disease (CKD) is unclear., Purpose: To determine the effect of ESAs on HRQOL at different hemoglobin targets in adults with CKD who were receiving or not receiving dialysis., Data Sources: Searches of PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to 1 November 2015, supplemented with manual screening., Study Selection: Randomized, controlled trials that evaluated the treatment of anemia with ESAs, including erythropoietin and darbepoetin, targeted higher versus lower hemoglobin levels, and used validated HRQOL metrics., Data Extraction: Study characteristics, quality, and data were assessed independently by 2 reviewers. Outcome measures were scores on the Short Form-36 Health Survey (SF-36), Kidney Dialysis Questionnaire (KDQ), and other tools., Data Synthesis: Of 17 eligible studies, 13 reported SF-36 outcomes and 4 reported KDQ outcomes. Study populations consisted of patients not undergoing dialysis (n = 12), those undergoing dialysis (n = 4), or a mixed sample (n = 1). Only 4 studies had low risk of bias. Pooled analyses showed that higher hemoglobin targets resulted in no statistically or clinically significant differences in SF-36 or KDQ domains. Differences in HRQOL were further attenuated in studies at low risk of bias and in subgroups of dialysis recipients., Limitation: Statistically significant heterogeneity among studies, few good-quality studies, and possible publication bias., Conclusion: ESA treatment of anemia to obtain higher hemoglobin targets does not result in important differences in HRQOL in patients with CKD., Primary Funding Source: KRESCENT and Manitoba Health Research Council Establishment.

Background: Early identification of high-grade ischemia based on echocardiographic diastolic abnormalities may be clinically useful in the acute coronary syndrome (ACS) setting. This could provide the clinician with an awareness of the burden of coronary artery disease (CAD) before angiography is performed to allow for early intervention of suspected ischemic lesions. The objective of the study was to assess whether 2D transthoracic echocardiography (TTE)-derived tissue Doppler imaging parameters can predict the severity of CAD in comparison with the cardiac catheterization-derived SYNTAX score., Methods: A retrospective study of 74 stable angina or patients with ACS was performed in 2012 at a single tertiary care center. In all study subjects, TTE and angiography were performed within 6 months of each other without revascularization in the interim., Results: The study population included a total of 74 patients (mean age 67 ± 12 years) with 77% presenting with an ACS. The median SYNTAX score was 24.0 (6.0-35.0). The E-wave velocity was higher, and deceleration time (DT) was lower in the high SYNTAX group in comparison with the low/intermediate SYNTAX group (P = 0.045 and P = 0.001, respectively). Septal mitral annular S' was lower in the high SYNTAX group (P = 0.02). After multivariate analysis, E/A ratio (OR 0.03, 95% 0.00-0.36, P = 0.0067), DT (OR 0.93, 95% CI 0.89-0.97, P = 0.0001) and septal annular S'-wave velocity (OR 0.34, 95% CI 0.16-0.71, P = 0.0038) remained strong predictors of a high SYNTAX score., Conclusion: Early identification of systolic and diastolic dysfunction based on echocardiographic parameters may be of important clinical significance for predicting CAD burden prior to invasive angiography., (© 2015, Wiley Periodicals, Inc.)

Background: Early accurate detection of acute kidney injury (AKI) occurring after cardiac surgery may improve morbidity and mortality. Although several novel biomarkers have been developed for the early detection of AKI, their clinical utility in the critical intraoperative and immediate postoperative period remains unclear., Study Design: Systematic review and meta-analysis., Setting & Population: Adult patients having cardiac surgery., Selection Criteria for Studies: EMBASE, CINAHL, Cochrane Library, Scopus, and PubMed from January 1990 until January 2015 were systematically searched for cohort studies reporting the utility of novel biomarkers for the early diagnosis of AKI after adult cardiac surgery. Reviewers extracted data for study design, population, timing of biomarker measurement and AKI occurrence, biomarker performance (area under the receiver operating characteristic curve [AUROC]), and risk of bias., Index Tests: Novel urine, plasma, and serum AKI biomarkers, measured intraoperatively and in the early postoperative period (<24 hours)., Reference Tests: AKI was defined according to the RIFLE, AKIN, or 2012 KDIGO criteria., Results: We found 28 studies reporting intraoperative and/or early postoperative measurement of urine (n=23 studies) or plasma or serum (n=12 studies) biomarkers. Only 4 of these studies measured biomarkers intraoperatively. Overall, intraoperative discrimination by the urine biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury marker 1 (KIM-1) demonstrated AUROCs<0.70, whereas N-acetyl-β-d-glucosaminidase (NAG) and cystatin C had AUROCs<0.75. In the immediate 24-hour postoperative period, the urine biomarkers NGAL (16 studies), KIM-1 (6 studies), and liver-type fatty acid binding protein (6 studies) exhibited composite AUROCs of 0.69 to 0.72. The composite AUROCs for postoperative urine cystatin C, NAG, and interleukin 18 were ≤0.70. Similarly, the composite AUROCs for postoperative plasma NGAL (6 studies) and cystatin-C (5 studies) were <0.70., Limitations: Heterogeneous AKI definitions., Conclusions: In adults, known urinary, plasma, and serum biomarkers of AKI possess modest discrimination at best when measured within 24 hours of cardiac surgery., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Ex vivo heart perfusion (EVHP) may facilitate resuscitation of discarded donor hearts and expand the donor pool; however, a reliable means of demonstrating organ viability prior to transplantation is required. Therefore, we sought to identify metabolic and functional parameters that predict myocardial performance during EVHP. To evaluate the parameters over a broad spectrum of organ function, we obtained hearts from 9 normal pigs and 37 donation after circulatory death pigs and perfused them ex vivo. Functional parameters obtained from a left ventricular conductance catheter, oxygen consumption, coronary vascular resistance, and lactate concentration were measured, and linear regression analyses were performed to identify which parameters best correlated with myocardial performance (cardiac index: mL·min(-1)·g(-1)). Functional parameters exhibited excellent correlation with myocardial performance and demonstrated high sensitivity and specificity for identifying hearts at risk of poor post-transplant function (ejection fraction: R(2) = 0.80, sensitivity = 1.00, specificity = 0.85; stroke work: R(2) = 0.76, sensitivity = 1.00, specificity = 0.77; minimum dP/dt: R(2) = 0.74, sensitivity = 1.00, specificity = 0.54; tau: R(2) = 0.51, sensitivity = 1.00, specificity = 0.92), whereas metabolic parameters were limited in their ability to predict myocardial performance (oxygen consumption: R(2) = 0.28; coronary vascular resistance: R(2) = 0.20; lactate concentration: R(2) = 0.02). We concluded that evaluation of functional parameters provides the best assessment of myocardial performance during EVHP, which highlights the need for an EVHP device capable of assessing the donor heart in a physiologic working mode.

Purpose: The novel high-sensitivity troponin T assay (hs-cTnT) has been validated for diagnosing AMI in the emergency room. However its utility in high-risk in-patient populations is unknown., Methods: We retrospectively reviewed admissions to a general cardiology unit that had 2 hs-cTnT measurements in the first 12 h of presentation. We assessed 8 diagnostic algorithms that used hs-cTnT concentration and changes in concentration (including the 99th percentile cut-off of 14 ng/L) for their diagnostic utility in separating AMI patients from cardiac/nonACS and non-cardiac chest-pain patients. UA was excluded., Results: There were 233 patients (mean age 67 years, 153 were males (66%)) admitted over a 2 month period, with AMI diagnosed in 118 of these patients (51%). The recommended 99th percentile cut-off had modest accuracy (65%), good sensitivity (88%), and poor specificity (25%); a higher cut-off of 75 ng/L had a better diagnostic accuracy of 73%, p < 0.05. While some hs-cTnT algorithms were either highly sensitive or specific, none were both., Conclusion: In high-risk cardiology in-patients, no hs-cTnT concentration cut-off or change more accurately diagnosed and excluded AMI, although higher cut-offs had better diagnostic utility.

Objective: To determine if adding frailty measures to the EuroSCORE II improves model performance in predicting postoperative delirium., Methods: In a prospective observational study in elective cardiac surgery patients, frailty was defined using the Modified Fried Criteria (MFC), the Short Physical Performance Battery (SPPB) and a 35-item Frailty Index (FI). The primary outcome was postoperative delirium, assessed using the Confusion Assessment Method (CAM)., Results: Seventy-two (54.1%) of the 133 participants met the MFC definition for frailty and 69 (51.9%) met the SPPB definition. Eighty-eight (66.2%) participants had an FI score ≥ 0.2, and 47 (35.3%) had a score ≥ 0.3. After adjusting for the EuroSCORE II, frail patients as identified by the MFC were at increased risk of postoperative delirium (adjusted odds ratio [OR], 5.05, 95% confidence interval [CI], 1.58-16.13). Patients in the "high risk frailty" SPPB category had even greater risk (adjusted OR, 8.26, 95% CI, 2.23-30.64). FI scores ≥ 0.3 were also associated with higher risk of delirium (adjusted OR, 3.72, 95% CI, 1.39-9.92). The inclusion of any of these definitions of frailty improved the discrimination of the EuroSCORE II in predicting postoperative delirium., Conclusions: Frailty results in a 3- to 8-fold increase in risk of postoperative delirium, independent of the EuroSCORE II. "Frail" and "fit" may be considered 2 ends of a continuum, and the risk of postoperative delirium grows as one becomes increasingly frail. The addition of frailty improves the ability of the EuroSCORE II to predict postoperative delirium, pointing to opportunities for improved prevention and management., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Among patients with reversible conditions who sustain cardiac arrest, extracorporeal membrane oxygenation (ECMO) may support end organ perfusion while bridging to definitive therapy., Methods: A single center retrospective review (February 2008–September 2013) of adults receiving ECMO for cardiac arrest ≥15 min duration refractory to conventional management (E-CPR) or profound cardiogenic shock following IHCA (E-CS) was conducted. The primary outcome was 30-day survival with good neurologic function defined as a cerebral performance category (CPC) of 1–2. Secondary outcomes included intensive care unit (ICU) and hospital length of say, duration of mechanical ventilation, and univariate predictors of 30-day survival with favorable neurologic function., Results: Thirty-two patients (55 ± 11 years, 66% male) were included of which 22 (69%) received E-CPR and 10 (31%) received E-CS following return of spontaneous circulation (ROSC). Cardiac arrest duration was 48.8 ± 21 min for those receiving E-CPR and 25 ± 23 min for the E-CS group. Patients received ECMO support for 70.7 ± 47.6 h. Death on ECMO support occurred in 7 (21.9%) patients, while 7 (21.9%) were bridged to another form of mechanical circulatory support, and 18 (56.3%) were successfully decannulated. ICU length of stay was 7.5 [3.3–14] days and ICU survival occurred in 16 (50%) of patients. 30-Day survival was 5 (50%) in the E-CS group, 10 (45.4%) in the E-CPR group, and 15 (47%) overall. All survivors had CPC 1–2 neurologic status., Conclusion: In this single center experience, the use of resuscitative ECMO was associated with neurologically favorable 30-day survival in 47% of patients with prolonged IHCA (H2012:172).

Objectives: Post-operative nausea and vomiting (PONV) is a common and distressing complication following cardiac surgery. Therefore, our primary objective was to explore the predictors of severe PONV in the cardiac surgery population., Methods: A retrospective study was completed on cardiac surgery patients (N = 150). A modified preoperative PONV risk assessment tool was utilized to identify patients at high and low risk for PONV., Results: 54% of the high-risk group versus 13% of the low-risk group experienced ≥2 nausea events in the early post-operative period (p < 0.0001). The high-risk group had a uniquely elevated and sustained number of PONV events post-operatively. History of PONV (p = 0.03) and female gender (p = 0.01) emerged as significant predictors of any nausea event., Conclusions: A specific PONV risk assessment tool may be useful for predicting those at highest risk following cardiac surgery. Further research is required to identify strategies to reduce PONV., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objectives: This study reports the results a novel radiation reduction protocol (RRP) system for coronary angiography and interventional procedures and the determinants of radiation dose., Background: The cardiac catheterization laboratory is an important source of radiation and should be kept in good working order with dose-reduction and monitoring capabilities., Methods: All diagnostic coronary angiograms and percutaneous coronary interventions from a single catheterization laboratory were analyzed 2 months before and after RRP implementation. The primary outcome was the relative dose reduction at the interventional reference point. Separate analyses were done for conventional 15 frames/s (FPS) and at reduced 7.5 FPS post-RRP groups., Results: A total of 605 patients underwent coronary angiography (309 before RRP and 296 after RRP), with 129 (42%) and 122 (41%) undergoing percutaneous coronary interventions before and after RRP, respectively. With RRP, a 48% dose reduction (1.07 ± 0.05 Gy vs. 0.56 ± 0.03 Gy, p < 0.0001) was obtained, 35% with 15 FPS RRP (0.70 ± 0.05 Gy, p < 0.0001) and 62% with 7.5 FPS RRP (0.41 ± 0.03 Gy, p < 0.001). Similar dose reductions for diagnostic angiograms and percutaneous coronary interventions were noted. There was no change in the number of stents placed or vessels intervened on. Increased dose was associated with male sex, radial approach, increasing body mass index, cine runs, and frame rates. Using a multivariable model, a 48% relative risk with RRP (p < 0.001), 44% with 15 FPS RRP and 68% with 7.5 FPS RRP was obtained., Conclusions: We demonstrate a highly significant 48.5% adjusted radiation dose reduction using a novel algorithm, which needs strong consideration among interventional cardiology practice., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Peritoneal dialysis is associated with similar survival and similar improvement in quality of life and is less costly compared with in-centre hemodialysis. We examined facility and geographic variation in the use of peritoneal dialysis in Canada., Methods: We analyzed data from the Canadian Organ Replacement Register for the period January 2001 to December 2010. We identified patients for whom peritoneal dialysis was the primary modality at 90 days after initiation of dialysis. We used multilevel models to evaluate variation in use of peritoneal dialysis by facility and geographic region., Results: We analyzed data for 31 778 incident dialysis patients at 56 facilities in 13 geographic regions across Canada. Use of peritoneal dialysis at 90 days varied considerably across geographic regions (range 19.8%-36.1%) and declined over time, from 28.8% in 2001 to 22.5% in 2010. After adjustment for case mix and facility-level quality indicators, 9.3% and 3.4% of the variability was attributable to facility and geographic factors, respectively. In adjusted models, there was a substantial difference between geographic regions with the lowest and highest peritoneal dialysis use (odds ratio for high use 1.51, 95% confidence interval [CI] 1.33-1.73 v. odds ratio for low use 0.69, 95% CI 0.60-0.79)., Interpretation: In Canada, substantial variability in the use of peritoneal dialysis attributable to facility and geographic region was not explained by differences in patient case mix. An opportunity exists to optimize use of this cost-effective therapy through changes in policy and standardization of criteria for initiation of peritoneal dialysis.

Background: Compared with non-ST-elevation myocardial infarction (MI), ST-elevation MI has been associated with increased mortality after medical treatment and percutaneous coronary intervention. Our study investigated the prognostic value of MI classification in the setting of surgical revascularization within 21 days of MI., Methods: We studied 2412 consecutive patients between 1995 and 2007 who underwent an isolated coronary artery bypass grafting procedure within 21 days after MI. The outcomes of interest were in-hospital mortality and major adverse events, which included death, MI, stroke, and renal failure requiring hemodialysis., Results: Rates of crude in-hospital mortality and major adverse events were higher in ST-elevation MI patients. Stepwise regression analysis suggested that MI subtype (ST-elevation MI vs non-ST-elevation MI) did not predict in-hospital mortality or major adverse events. A secondary analysis using propensity score matching showed similar surgical outcomes between the two cohorts., Conclusions: Surgical risks of patients with recent MI are independent of MI subtype. Distinguishing ST-elevation MI and non-ST-elevation MI is of limited value in the decision-making process of early surgical intervention., (Copyright 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)