Plants against pathogens: Effect of significant antimicrobial-producing plants on faecal microbe inactivation throughout the soil profile of stormwater biofilters.

Stormwater biofilters have demonstrated promising yet variable removal of faecal microorganisms. Significant antimicrobial-producing plants have been proposed as an inexpensive, safe and easily adaptable component of biofilter design to enhance faecal pathogen treatment. The aim of the present study was to investigate whether significant antimicrobial-producing plants improved faecal bacterial inactivation throughout the biofilter soil profile, focusing on four key treatment zones. These were specifically the top sediment/surface layer; the rhizosphere (soil directly attached to and influenced by plant roots); bulk soil (soil not directly associated with roots); and the submerged/saturated zone. Biofilters were configured with either: (1) no plant; (2) Carex appressa, the most highly recommended plant species in Australian biofilter adoption guidelines; or (3) one of two significant antimicrobial-producing Australian plant species, Melaleuca linariifolia or Melaleuca fulgens (n = 3 each). Following 16 months' maturation, systems were dosed with semi-synthetic stormwater containing faecal bacteria Escherichia coli and Enterococcus faecalis to monitor their ensuing die-off within all major biofilter treatment zones. Bacterial inactivation was generally more rapid in M. fulgens and M. linariifolia than C. appressa biofilters, with E. faecalis demonstrating an overall enhanced resistance to inactivation. Top sediment tended to exhibit the highest inactivation rates, significantly correlated with sunlight exposure. Conversely, the rhizosphere supported comparatively prolonged faecal bacterial survival. The authors recommend further investigation of melaleucas and similar highly antimicrobial-producing plants for enhanced faecal pathogen treatment within biofilters and related treatment contexts.

Canadian Multicenter Chronic Total Occlusion Registry: Ten-Year Follow-Up Results of Chronic Total Occlusion Revascularization.

BACKGROUND: Chronic total occlusions (CTO) occur in nearly 20% of coronary angiograms. CTO revascularization, either by percutaneous coronary intervention (PCI) or coronary artery bypass grafting surgery (CABG), is infrequently performed, approximately one-third of cases. Long-term outcomes are unknown. The objective of the study was to determine whether early CTO revascularization of patients, either by CABG or PCI, was associated with improved clinical outcomes. METHODS: One thousand six hundred twenty-four patients from the Canadian CTO registry were followed for at least 9.75 years. Revascularization was performed according to routine clinical practice. Patients were grouped according to CTO revascularization status (PCI or CABG of CTO vessel, CTO revasc) or no CTO revasc (medical therapy only, or PCI/CABG of non-CTO vessels only), within 3 months of initial angiogram. Patients were followed for mortality, revascularization procedures (PCI and CABG), and hospitalizations for acute coronary syndromes and heart failure. RESULTS: Early CTO revasc was performed in 28.2% of patients (17.5% CABG, 10.7% PCI). The CTO revasc group was younger, with more males and generally fewer comorbidities. There was a significantly lower mortality probability at 10 years in the CTO revascularization group (22.7% [95% CI, 19.0%-26.9%]) compared with the no CTO revasc group (36.6% [95% CI, 33.8%-39.5%]). At 10 years, revascularization rates (14.0% versus 22.8%) and acute coronary syndrome hospitalization rates (10.0% versus 16.6%) were significantly lower in the CTO revasc group. Baseline-adjusted analysis showed CTO revasc was associated with significantly lower all-cause mortality (hazard ratio, 0.67 [95% CI, 0.54-0.84]). In both landmark and time varying analyses, association with lower mortality was particularly robust for CTO revascularization by CABG (hazard ratio 0.56 and 0.60, respectively), with a marginally significant result for PCI in the time varying analysis (hazard ratio 0.711 [95% CI, 0.51-0.998]). CONCLUSIONS: Early CTO revascularization was associated with significantly lower all-cause mortality, revascularization rates, and hospitalization for acute coronary syndrome at 10 years, and mainly driven by outcomes in patients with CABG.

Simple Laboratory Test-Based Risk Scores in Coronary Catheterization: Development, Validation, and Comparison to Conventional Risk Factors.

BACKGROUND: We developed and validated laboratory test-based risk scores (i.e., lab risk scores) to reclassify mortality risk among patients undergoing their first coronary catheterization. METHODS: Patients were catheterized between 2009 and 2015 in Calgary, Alberta, Canada (n = 14 135, derivation cohort), and in Edmonton, Alberta, Canada (n = 12 143, validation cohort). Logistic regression with group LASSO (least absolute shrinkage and selection operator) penalty was used to select quintiles of the last laboratory tests (red blood cell count, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, mean corpuscular volume, red cell distribution width, platelet count, total white blood cell count, plasma sodium, potassium, chloride, CO2, international normalized ratio, estimated glomerular filtration rate) performed <30 days before catheterization and by age and sex that were significantly associated with death ≤60 and >60 days after catheterization. Follow-up was until 2016. Risk scores were developed from significant tests, internally validated in Calgary among bootstrap samples and externally validated in Edmonton after recalibration using coefficients developed in Calgary. Interaction tests were performed, and net reclassification improvement vs conventional demographic and clinical risk factors was determined. RESULTS: Lab risk scores were strongly associated with mortality (29-40× for top vs bottom quintile, P for trends <0.01), had good discrimination and were well calibrated in Calgary (C = 0.80-0.85, slope = 0.99-1.01) and Edmonton (C = 0.80-0.82; slope = 1.02-1.05)-similar to demographic and clinical risk factors alone. Associations were attenuated by several comorbidities; however, scores appropriately reclassified 11%-20% of deaths (both follow-up periods) and 6%-9% of survivors (>60 days) after catheterization vs demographic and clinical risk factors. CONCLUSIONS: In 2 populations of patients undergoing their first coronary catheterization, risk scores based on simple laboratory tests were as powerful as a combination of demographic and clinical risk factors in predicting mortality. Lab risk scores should be used for patients undergoing coronary catheterization.

Rise of the killer plants: investigating the antimicrobial activity of Australian plants to enhance biofilter-mediated pathogen removal.

BACKGROUND: Biofilters are soil-plant based passive stormwater treatment systems which demonstrate promising, although inconsistent, removal of faecal microorganisms. Antimicrobial-producing plants represent a safe, inexpensive yet under-researched biofilter design component that may enhance treatment reliability. The mechanisms underlying plant-mediated microbial removal in biofilters have not been fully elucidated, particularly with respect to antimicrobial production. The aim of this study was therefore to inform biofilter vegetation selection guidelines for optimal pathogen treatment by conducting antimicrobial screening of biofilter-suitable plant species. This involved: (1) selecting native plants suitable for biofilters (17 species) in a Victorian context (southeast Australia); and (2) conducting antimicrobial susceptibility testing of selected plant methanolic extracts (≥ 5 biological replicates/species; 86 total) against reference stormwater faecal bacteria (Salmonella enterica subsp. enterica ser. Typhimurium, Enterococcus faecalis and Escherichia coli). RESULTS: The present study represents the first report on the inhibitory activity of polar alcoholic extracts from multiple tested species. Extracts of plants in the Myrtaceae family, reputed for their production of antimicrobial oils, demonstrated significantly lower minimum inhibitory concentrations (MICs) than non-myrtaceous candidates (p < 0.0001). Melaleuca fulgens (median MIC: 8 mg/mL; range: [4-16 mg/mL]), Callistemon viminalis (16 mg/mL, [2-16 mg/mL]) and Leptospermum lanigerum (8 mg/mL, [4-16 mg/mL]) exhibited the strongest inhibitory activity against the selected bacteria (p < 0.05 compared to each tested non-myrtaceous candidate). In contrast, the Australian biofilter gold standard Carex appressa demonstrated eight-fold lower activity than the highest performer M. fulgens (64 mg/mL, [32-64 mg/mL]). CONCLUSION: Our results suggest that myrtaceous plants, particularly M. fulgens, may be more effective than the current vegetation gold standard in mediating antibiosis and thus improving pathogen treatment within biofilters. Further investigation of these plants in biofilter contexts is recommended to refine biofilter vegetation selection guidelines.

Impact of clinical presentation and presence of coronary sclerosis on long-term outcome of patients with non-obstructive coronary artery disease.

BACKGROUND: Non-obstructive coronary artery disease (NOCAD) is a common finding on coronary angiography. Our goal was to evaluate the long-term prognosis of NOCAD patients with stable angina (SA). METHODS: The study cohort consisted of 7478 NOCAD patients with normal EF (≥ 50%), and SA who underwent coronary angiography between 1995 and 2012. We compared NOCAD patients (stenosis< 50%) with 10,906 patients with stable obstructive CAD (≥ 50%). The primary endpoint was all-cause mortality. Secondary endpoints included repeat angiography, progressive CAD, and PCI. A second comparison group consisted of 7344 patients with NOCAD presenting with an ACS. Rates of all-cause mortality of NOCAD ACS patients were compared to NOCAD SA patients. RESULTS: Median follow-up time was 6.5 years. NOCAD patients had a lower risk of all-cause mortality compared to CAD patients (HR CAD vs. NOCAD 1.33 (1.19-1.49); p < 0.001). This was driven by patients with normal coronary arteries (HR CAD vs. normal 1.63 (1.36-1.94), p < 0.001), whereas patients with minimal disease (> 0% and < 50%) were at similar risk as CAD patients (HR CAD vs. minimal 1.08 (0.99-1.29), p = 0.06). In NOCAD patients, the strongest predictors of all-cause mortality were age and minimal disease. SA patients with NOCAD had low rates of repeat angiography (7.3%), future CAD (2.3%) and PCI (1.7%). NOCAD ACS patients had a 41% increase in all-cause mortality risk compared to NOCAD SA patients (HR 1.41 (1.25-1.6), p < 0.001). CONCLUSIONS: This study underlines the importance of minimal CAD, as it is not a benign disease entity and portends a similar risk as stable obstructive CAD.

Patient perspectives on engagement in decision-making in early management of non-ST elevation acute coronary syndrome: a qualitative study.

BACKGROUND: Surveys of patients suggest many want to be actively involved in treatment decisions for acute coronary syndromes. However, patient experiences of their engagement and participation in early phase decision-making have not been well described. METHODS: We performed a patient led qualitative study to explore patient experiences with decision-making processes when admitted to hospital with non-ST elevation acute coronary syndrome. Trained patient-researchers conducted the study via a three-phase approach using focus groups and semi-structured interviews and employing grounded theory methodology. RESULTS: Twenty patients discharged within one year of a non-ST elevation acute coronary syndrome participated in the study. Several common themes emerged. First, patients characterized the admission and early treatment of ACS as a rapidly unfolding process where they had little control. Participants felt they played a passive role in early phase decision-making. Furthermore, participants described feeling reduced capacity for decision-making owing to fear and mental stress from acute illness, and therefore most but not all participants were relieved that expert clinicians made decisions for them. Finally, once past the emergent phase of care, participants wanted to retake a more active role in their treatment and follow-up plans. CONCLUSIONS: Patients admitted with ACS often do not take an active role in initial clinical decisions, and are satisfied to allow the medical team to direct early phase care. These results provide important insight relevant to designing patient-centered interventions in ACS and other urgent care situations.

Serum Total 25-OH Vitamin D Adds Little Prognostic Value in Patients Undergoing Coronary Catheterization.

BACKGROUND: Vitamin D deficiency is associated with an increased risk of cardiovascular disease; however, it is unclear whether vitamin D status should be considered in clinical risk assessments of patients with cardiovascular disease. METHODS AND RESULTS: This study included 2975 patients who had their first serum total 25-hydroxy vitamin D (25-OH vitamin D) measurement before their first coronary catheterization in Alberta, Canada. Cox regression was used to examine associations between 25-OH vitamin D and mortality risk after adjusting for demographic and clinical risk factors. Interactions were tested using multiplicative terms, and prognostic value was assessed using measures of model discrimination, fit, calibration and net reclassification improvement. There were 401 deaths over a median of 5.8 years of follow-up. Serum total 25-OH vitamin D was inversely associated with mortality after adjusting for demographic and clinical risk factors, which was largely driven by excess risk in the bottom quintile (hazard ratio 1.84 for bottom versus top quintile, 95% CI 1.36-2.50, P for trend <0.001). Associations were weaker in the presence of several competing risk factors (e.g., advanced age; P for interactions <0.05). Adding 25-OH vitamin D to a model containing demographic and clinical risk factors yielded similar discrimination, model fit, and calibration and only modest improvements in risk reclassification (net reclassification improvement 1.9% for deaths, 2.3% for survivors). CONCLUSIONS: Pre-catheterization, serum total 25-OH vitamin D was inversely associated with mortality risk after adjusting for established demographic and clinical risk factors. This association was attenuated by several competing risk factors. Overall, 25-OH vitamin D added little prognostic value over established risk factors; therefore, its measurement is not warranted in patients undergoing coronary catheterization.

Gender differences in the prevalence and treatment of coronary chronic total occlusions.

BACKGROUND: Gender differences exist in the presentation and outcomes of patients with coronary artery disease (CAD). Our study objective was to compare gender differences in prevalence, co-morbidities, and revascularization treatment in CAD patients with chronic total occlusions (CTOs). METHODS: A retrospective analysis using the Canadian Multicenter CTO Registry, which included 1,690 consecutive CTO patients identified at coronary angiography and a control group of 7,682 non-CTO patients. RESULTS: The prevalence of women in the CTO group was significantly lower compared to the control group (19% vs. 30%, P < 0.001). Within the overall CTO group, women were significantly older than men (70 ± 12 vs. 66 ± 11 years, P < 0.001) with more comorbidities, including hypertension and heart failure. Rates of PCI in the CTO group were similar between gender (10%), however, women with CTO were treated significantly less by CABG compared to men (19% vs. 27%, P = 0.003). Moreover, compared to male patients, significantly fewer women undergoing CABG had revascularization of the CTO artery (84% vs. 93%, P = 0.03). Multivariable analysis indicated that female gender (along with age, chronic renal failure, prior MI and cerebro-vascular disease) were independent predictors for not receiving CABG treatment for CTO. CONCLUSIONS: Female gender differences exist in CTO patients with both lower prevalence of CTOs at angiography and lower revascularization rates of CTOs by CABG. © 2015 Wiley Periodicals, Inc.

Characterizing types of readmission after acute coronary syndrome hospitalization: implications for quality reporting.

BACKGROUND: Thirty-day readmission rates have been tied to hospital reimbursement in the United States, but remain controversial as measures of healthcare quality. We profile the timing, main diagnoses, and survival outcomes of inpatient and emergency department readmissions after acute coronary syndrome (ACS), based on a large regional database. METHODS AND RESULTS: Patients enrolled in the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) registry with an ACS hospitalization between April 2008 and March 2010 (n=3411) were included. Primary outcomes were inpatient and emergency department-only readmissions, at 30 days and 1 year. Predictors of 30-day readmission were identified, and the association between 30-day readmission status and mortality was evaluated. A total of 1170 (34.3%) patients had ≥1 hospital readmission within 30 days, reaching 2106 (61.7%) within 1 year of ACS discharge. Of first readmissions, 45% were emergency department only and 53% were for cardiovascular or possibly related diagnoses. Renal disease and diabetes predicted all-cause readmissions at 30 days and 1 year, but there were no robust predictors of cardiovascular readmissions. Thirty-day inpatient, but not emergency department, readmissions were associated with increased mortality. CONCLUSIONS: Hospital readmissions within 30 days after discharge for ACS are common, and associated with increased mortality. However, our findings underline that readmissions are quite heterogeneous in nature, and that many readmissions are unrelated to index stay and thus not easily predicted with common clinical variables. All-cause 30-day readmission rates may be too simplistic, and perhaps even misleading, as a hospital performance metric.

Relationship between initial treatment strategy and quality of life in patients with coronary chronic total occlusions.

AIMS: Our objective was to evaluate the relationship between coronary chronic total occlusion (CTO) treatment strategy and quality of life improvements. METHODS AND RESULTS: This multicentre prospective cohort study enrolled consecutive CTO patients undergoing a non-urgent coronary angiogram who completed the Seattle Angina Questionnaire (SAQ) and EQ-5D at baseline and at one year. Strategies were: i) medical therapy, ii) PCI to non-CTO, iii) PCI to CTO, and iv) CABG. Multivariable regression models compared quality of life changes over time among strategies, accounting for repeat measures per patient. In our cohort of 387 patients, 154 underwent medical therapy, 83 had PCI to the non-CTO artery, 104 underwent CABG, and 46 underwent PCI to the CTO. Medically treated patients had no improvement on any SAQ domains. Patients with revascularisation of the CTO territory with either PCI or CABG had significant improvements in the physical limitation (PCI to CTO 60.5-76.4; CABG 61.6-80.1; p<0.001), angina frequency (PCI to CTO 79.0-92.7; CABG 82.1-97.9; p<0.001), and disease perception (PCI to CTO 50.5-75.0; CABG 50.2-80.0; p<0.001) domains. In non-CTO PCI patients, improvement was restricted to the angina frequency (82.8-93.3; p<0.001), and disease perception (53.8-71.4; p<0.001) domains. CONCLUSIONS: CTO territory revascularisation was associated with quality of life improvements.

Frailty and outcome in elderly patients with acute coronary syndrome.

BACKGROUND: Frailty is superior to chronological age as a predictor of outcome. The Edmonton Frail Scale (EFS) is a simple valid measure of frailty, covering multiple important domains, with scores ranging from 0 (not frail) to 17 (very frail). The purpose of this pilot study was to assess the EFS in a group of elderly patients with acute coronary syndrome (ACS). METHODS: The EFS was administered to 183 consecutive patients with ACS aged ≥ 65 years admitted to a single centre in Edmonton, Alberta, Canada. RESULTS: Scores ranged from 0-13. Patients with higher EFS scores were older, with more comorbidities, longer lengths of stay (EFS 0-3: mean, 7.0 days; EFS 4-6: mean, 9.7 days; and EFS ≥ 7: mean, 12.7 days; P = 0.03), and decreased procedure use. Crude mortality rates at 1 year were 1.6% for EFS 0-3, 7.7% for EFS 4-6, and 12.7% for EFS ≥ 7 (P = 0.05). After adjusting for baseline risk differences using a "burden of illness" score, the hazard ratio for mortality for EFS ≥ 7 compared with EFS 0-3 was 3.49 (95% confidence interval [CI], 1.08-7.61; P = 0.002). CONCLUSIONS: The EFS is associated with increased comorbidity, longer lengths of stay, and decreased procedure use. After adjustment for burden of illness, the highest frailty category is independently associated with mortality in elderly patients with ACS. Further work is needed to determine whether the use of a validated frailty instrument would better delineate medical decision making in this important, often disadvantaged population.

Time dependency of outcomes for drug-eluting vs bare-metal stents.

BACKGROUND: Previous research suggests that the early benefit from revascularization with drug-eluting stents might diminish over time. METHODS: We performed an extended analysis of a previously identified cohort of 6440 patients who underwent percutaneous coronary intervention between April 1, 2003 and March 31, 2005 using a prospective provincial clinical registry in Alberta, Canada. We compared rates of death, and of death or repeat revascularization among the 6440 patients receiving either drug-eluting (sirolimus- and paclitaxel) stents or bare-metal stents. We determined risk-adjusted hazard ratios at moments in time with a spline analysis using Cox proportional hazards modelling. RESULTS: During the 8 years of observation, the relative risks for death or the composite outcome of death or repeat revascularization varied over time. There was an early finding of better outcomes associated with drug-eluting stents in the first year after implantation. Thereafter, there was no significant benefit associated with drug-eluting stents compared with bare-metal stents with 8 years of follow-up. At 30 days, the adjusted hazard ratio was 0.38 (95% confidence interval [CI], 0.18-0.81) for death and 0.27 (95% CI, 0.14-0.54) for the composite outcome of death or repeat revascularization. By 8 years, the adjusted hazard ratio of death or the composite outcome was 1.15 (95% CI, 0.97-1.36) and 1.01 (95% CI, 0.87-1.17), respectively. CONCLUSIONS: Revascularization with first-generation drug-eluting stents is associated with better outcomes within the first year only. Thereafter, the risk of death or repeat revascularization is similar between drug-eluting stents and bare-metal stents.

Determinants of percutaneous coronary intervention vs coronary artery bypass grafting: an interprovincial comparison.

BACKGROUND: Marked variation exists concerning the utilization of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The objective of this study was to examine differences in predictors of mode of revascularization across 3 provincial jurisdictions. METHODS: All patients who underwent PCI and isolated CABG in British Columbia, Alberta, and Nova Scotia between 1996 and 2007 were considered. Age- and sex-standardized rates of PCI and CABG per 100,000 population and PCI to CABG ratios were calculated by year and province. Logistic regression models were constructed to identify independent predictors of mode of revascularization in each province. RESULTS: A total of 32,190 and 69,409 patients underwent CABG and PCI, respectively, during the study period. Significant increases in the age- and sex-adjusted PCI to CABG ratios were observed in all 3 provinces, but these ratios differed between provinces. Across all 3 jurisdictions, female sex and diagnosis of acute coronary syndrome favoured increased PCI vs CABG, and increased age, left main, or 3-vessel disease occurring before myocardial infarction, and diabetes favoured lower PCI vs CABG. After adjusting for clinical and angiographic factors, there remained a significant variation in choice of PCI vs CABG between the 3 provinces over time. CONCLUSIONS: Significant interprovincial variability in PCI to CABG ratios was observed. Though certain patient-related factors predictive of either PCI or CABG were identified, factors beyond clinical presentation played a role in the choice of revascularization approach.

Renal outcomes associated with invasive versus conservative management of acute coronary syndrome: propensity matched cohort study.

OBJECTIVES: To examine the association of early invasive management of acute coronary syndrome with adverse renal outcomes and survival, and to determine whether the risks or benefits of early invasive management differ in people with pre-existing chronic kidney disease. DESIGN: Propensity score matched cohort study. SETTING: Acute care hospitals in Alberta, Canada, 2004-09. PARTICIPANTS: 10,516 adults with non-ST elevation acute coronary syndrome. INTERVENTIONS: Participants were stratified by baseline estimated glomerular filtration rate and matched 1:1 on their propensity score for early invasive management (coronary catheterisation within two days of hospital admission). MAIN OUTCOME MEASURES: Risks of acute kidney injury, kidney injury requiring dialysis, progression to end stage renal disease, and all cause mortality were compared between those who received early invasive treatment versus conservative treatment. RESULTS: Of 10,516 included participants, 4276 (40.7%) received early invasive management. After using propensity score methods to assemble a matched cohort of conservative management participants with characteristics similar to those who received early invasive management (n=6768), early invasive management was associated with an increased risk of acute kidney injury (10.3% v 8.7%, risk ratio 1.18, 95% confidence interval 1.03 to 1.36; P=0.019), but no difference in the risk of acute kidney injury requiring dialysis (0.4% v 0.3%, 1.20, 0.52 to 2.78; P=0.670). Over a median follow-up of 2.5 years, the risk of progression to end stage renal disease did not differ between the groups (0.3 v 0.4 events per 100 person years, hazard ratio 0.91, 95% confidence interval 0.55 to 1.49; P=0.712); however, early invasive management was associated with reduced long term mortality (2.4 v 3.4 events per 100 person years, 0.69, 0.58 to 0.82; P<0.001). These associations were consistent among people with pre-existing reduced estimated glomerular filtration rate and with alternate definitions for early invasive management. CONCLUSIONS: Compared with conservative management, early invasive management of acute coronary syndrome is associated with a small increase in risk of acute kidney injury but not dialysis or long term progression to end stage renal disease.

Recent temporal trends and geographic distribution of cardiac procedures in Alberta.

BACKGROUND: Prior Canadian studies of cardiac procedure rates showed changes over time and regional variability, but more recent Canadian cardiac procedure rates are unknown. METHODS: We performed a study using the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry to evaluate the temporal trends and geographic distribution of cardiac procedures in Alberta from April 1, 2003 through March 31, 2010. Rates were age- and sex-standardized by means of the 1996 Canadian census. RESULTS: While the raw number of cardiac catheterizations in Alberta was nearly uniform through the study period, age- and sex-standardized cardiac catheterizations declined from a rate of 480 per 100,000 in 2003 to a rate of 430 per 100,000 in 2010. The percutaneous coronary intervention (PCI) rates also declined, from a rate of 186 per 100,000 in 2003 to 170 per 100,000 in 2010. The rates for coronary artery bypass grafts declined from 84 per 100,000 in 2003 to 42 per 100,000 in 2010. There was geographic variability, with northern regions characterized by rates that were higher than the provincial average rates, and southern regions characterized by rates lower than the provincial average. CONCLUSION: During the study period, age- and sex-standardized rates of cardiac catheterization and PCI in Alberta declined, reversing previous trends of increasing PCI rates. The rates of coronary artery bypass grafts in Alberta declined significantly, suggesting a change in practice consistent with that seen elsewhere. There are geographic differences in rates of cardiac procedures. These data have implications for other regions of Canada, for which registry data may not be available.

Cardiac rehabilitation attendance and outcomes in coronary artery disease patients.

BACKGROUND: Cardiac rehabilitation (CR) is an efficacious yet underused treatment for patients with coronary artery disease. The objective of this study was to determine the association between CR completion and mortality and resource use. METHODS AND RESULTS: We conducted a prospective cohort study of 5886 subjects (20.8% female; mean age, 60.6 years) who had undergone angiography and were referred for CR in Calgary, AB, Canada, between 1996 and 2009. Outcomes of interest included freedom from emergency room visits, hospitalization, and survival in CR completers versus noncompleters, adjusted for clinical covariates, treatment strategy, and coronary anatomy. Hazard ratios for events for CR completers versus noncompleters were also constructed. A propensity model was used to match completers to noncompleters on baseline characteristics, and each outcome was compared between propensity-matched groups. Of the subjects referred for CR, 2900 (49.3%) completed the program, and an additional 554 subjects started but did not complete CR. CR completion was associated with a lower risk of death, with an adjusted hazard ratio of 0.59 (95% confidence interval, 0.49-0.70). CR completion was also associated with a decreased risk of all-cause hospitalization (adjusted hazard ratio, 0.77; 95% confidence interval, 0.71-0.84) and cardiac hospitalization (adjusted hazard ratio, 0.68; 95% confidence interval, 0.55-0.83) but not with emergency room visits. Propensity-matched analysis demonstrated a persistent association between CR completion and reduced mortality. CONCLUSIONS: Among those coronary artery disease patients referred, CR completion is associated with improved survival and decreased hospitalization. There is a need to explore reasons for nonattendance and to test interventions to improve attendance after referral.

Current perspectives on coronary chronic total occlusions: the Canadian Multicenter Chronic Total Occlusions Registry.

OBJECTIVES: The purpose of this study was to determine the prevalence, clinical characteristics, and management of coronary chronic total occlusions (CTOs) in current practice. BACKGROUND: There is little evidence in contemporary literature concerning the prevalence, clinical characteristics, and treatment decisions regarding patients who have coronary CTOs identified during coronary angiography. METHODS: Consecutive patients undergoing nonurgent coronary angiography with CTO were prospectively identified at 3 Canadian sites from April 2008 to July 2009. Patients with previous coronary artery bypass graft surgery or presenting with acute ST-segment elevation myocardial infarction were excluded. Detailed baseline clinical, angiographic, electrocardiographic, and revascularization data were collected. RESULTS: Chronic total occlusions were identified in 1,697 (18.4%) patients with significant coronary artery disease (>50% stenosis in ≥1 coronary artery) who were undergoing nonemergent angiography. Previous history of myocardial infarction was documented in 40% of study patients, with electrocardiographic evidence of Q waves corresponding to the CTO artery territory in only 26% of cases. Left ventricular function was normal in >50% of patients with CTO. Half the CTOs were located in the right coronary artery. Almost half the patients with CTO were treated medically, and 25% underwent coronary artery bypass graft surgery (CTO bypassed in 88%). Percutaneous coronary intervention was done in 30% of patients, although CTO lesions were attempted in only 10% (with 70% success rate). CONCLUSIONS: Chronic total occlusions are common in contemporary catheterization laboratory practice. Prospective studies are needed to ascertain the benefits of treatment strategies of these complex patients.

Outcomes associated with bilateral internal thoracic artery grafting: the importance of age.

BACKGROUND: Although bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) is associated with low morbidity and good long-term results, controversy exists about the age after which BITA grafting is no longer beneficial. We sought to determine if such an age cutoff point exists. METHODS: The study cohort consisted of 5,601 consecutive patients from a cardiac surgery registry who underwent isolated CABG (1,038 [19%] BITA grafts, 4,029 [72%] single internal thoracic artery [SITA] grafts, 534 [10%] vein-only grafts) between 1995 and 2008. A Cox model was used to compare survival by use of bilateral, single, or no internal thoracic artery (ITA) grafts, adjusting for baseline clinical and demographic characteristics. RESULTS: Mean follow-up was 7.1 years. Patients undergoing BITA grafting had the lowest 1-year mortality (2.4% versus 4.3% SITA grafting and 8.2% vein-only grafting; p < 0.0001). Relative to SITA grafting, a crude survival benefit of 54% existed for BITA grafting (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.37 to 0.57; p < 0.0001) with worse survival for vein-only grafts (HR, 1.16; 95% CI, 0.99 to 1.37; p = 0.07). After adjustment, the benefit of BITA grafting was no longer statistically significant (HR, 0.87; 95% CI, 0.69 to 1.08; p = 0.2). However age may be an effect modifier: a spline analysis plotting HR (BITA grafting versus SITA grafting) against age suggested a potential survival advantage associated with BITA grafting in patients younger than 69.9 years. CONCLUSIONS: Bilateral internal thoracic artery grafting is a reasonable revascularization strategy in suitable patients up to age 70 years. As benefits of arterial grafting become more obvious over time, a longer period of follow-up will be needed to confirm the advantage of a BITA grafting strategy. In the meantime the BITA grafting advantage for patients older than 70 years is not clear.

The clinical profile and outcomes associated with coronary collaterals in patients with coronary artery disease.

BACKGROUND: The clinical correlates of coronary collaterals and the effects of coronary collaterals on prognosis are incompletely understood. METHODS: We performed a study of 55,751 patients undergoing coronary angiography to evaluate the correlates of angiographically apparent coronary collaterals, and to evaluate their association with survival. RESULTS: The characteristic most strongly associated with the presence of collaterals was a coronary occlusion (odds ratio [OR], 28.9; 95% confidence interval [CI], 27.1-30.6). Collaterals were associated with improved adjusted survival overall (hazard ratio [HR] 0.89; 95% CI, 0.85-0.95), and in both acute coronary syndrome (ACS) (HR 0.90; 95% CI, 0.84-0.96) and non-ACS (HR 0.84; 95% CI, 0.77-0.92) patients. Collaterals were associated with improved survival in those receiving angioplasty (HR 0.78; 95% CI, 0.71-0.85) and those with low risk anatomy treated medically (HR 0.84; 95% CI, 0.72-0.98), but not for those treated with coronary bypass graft surgery or those with high-risk anatomy treated without revascularization. CONCLUSIONS: The major correlate of coronary collaterals is the presence/extent of obstructive coronary artery disease. Collaterals are associated with better survival overall and in both ACS and non-ACS presentations, but not for those treated with coronary artery bypass graft (CABG) or those with high-risk anatomy who are not revascularized.

Invasive cardiac procedure use and mortality among South Asian and Chinese Canadians with coronary artery disease.

BACKGROUND: Previous studies evaluated cardiac procedure use and outcome over the short term, with relatively few Asian patients included. OBJECTIVES: To determine the likelihood of undergoing percutaneous coronary intervention and coronary artery bypass grafting, and survival during 10.5 years of follow-up after coronary angiography among South Asian, Chinese and other Canadian patients. METHODS: Using prospective cohort study data from two large Canadian provinces, 3061 South Asian, 1473 Chinese and 77,314 other Canadian patients with angiographically proven coronary artery disease from 1995 to 2004 were assessed, and their revascularization and mortality rates during 10.5 years of follow-up were determined. RESULTS: Compared with other Canadian patients, South Asian and Chinese patients were slightly less likely to undergo revascularization (riskadjusted HR 0.94, 95% CI 0.90 to 0.98 for South Asian patients; and HR 0.94, 95% CI 0.88 to 1.00 for Chinese patients). However, South Asian patients underwent coronary artery bypass grafting (HR 1.00, 95% CI 0.94 to 1.07) and Chinese patients underwent percutaneous coronary intervention (HR 0.96, 95% CI 0.89 to 1.04) as frequently as other Canadian patients. Although the 30-day mortality rate was similar across the three ethnic groups, the mortality rate in the follow-up period was significantly lower for South Asian patients (HR 0.76, 95% CI 0.61 to 0.95) and marginally lower for Chinese patients (HR 0.80, 95% CI 0.60 to 1.07) compared with other Canadian patients. CONCLUSIONS: South Asian and Chinese patients used revascularization slightly less but had better survival outcomes than other Canadian patients. The factors underlying the better outcomes for South Asian and Chinese patients warrant further study.