Karen Mackie
University Health Network
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Featured researches published by Karen Mackie.
American Heart Journal | 2008
Jonas Eichhöfer; Eric Horlick; Joan Ivanov; Peter H. Seidelin; John R. Ross; Douglas Ing; Paul Daly; Karen Mackie; Brenda Ridley; Leonard Schwartz; Alan Barolet; Vladimír Džavík
BACKGROUND Studies evaluating the efficacy and safety of the transradial approach for percutaneous coronary intervention (PCI) were carried out mainly before the widespread use of stents and glycoprotein (GP) IIb/IIIa inhibitors. We sought to determine the association between the choice of the vascular access site and procedural complications after PCI performed with routine stenting and GP IIb/IIIa inhibition. METHODS The data source was a prospective registry of 13,499 consecutive cases of PCI at the University Health Network, Toronto, Canada, from April 2000 to September 2006. Logistic regression was used to calculate the probability of selection to the radial access group. Using propensity score methodology, 3,198 patients with femoral access were randomly matched to 3,198 patients with radial access based on clinical, angiographic, and procedural characteristics. Multivariable logistic regression analysis was used to identify the independent predictors of access site-related complications. Major adverse cardiac event was defined as death, myocardial infarction, abrupt vessel closure, or coronary artery bypass surgery. RESULTS Use of the transradial approach was associated with fewer vascular access complications (1.5% vs 0.6%, P<.001) and a shorter length of hospital stay. Multivariable analysis revealed transradial access (OR 0.39, 95% CI 0.2-0.7) to be an independent predictor of lower risk, whereas primary PCI (OR 4.36, 95% CI 1.4, 13), recent myocardial infarction (OR 2.0 95% CI 1.2, 3.4), age (per 10 years increase: OR 1.37, 95% CI 1.1-1.7) and female gender (0R 2.78 95% CI 1.7, 4.6) were independent predictors of a higher risk of access site complications. CONCLUSIONS Use of transradial access for PCI is safe and is independently associated with a reduced rate of in-hospital access site complications and reduced length of hospital stay.
American Heart Journal | 1998
Warren J. Cantor; Charles Lazzam; Eric A. Cohen; Kimberley A. Bowman; Sharon Dolman; Karen Mackie; Madhu K. Natarajan; Bradley H. Strauss
BACKGROUND Coronary stent deployment failure may be more common in clinical practice than generally appreciated. The incidence of failed deployment in routine clinical practice and the clinical sequelae have not been described. This study sought to determine the incidence and consequences of failed coronary stent deployment and to identify clinical and angiographic characteristics associated with deployment failure. METHODS AND RESULTS A series of 1303 consecutive procedures involving attempted coronary stenting were reviewed retrospectively. Failed stent deployment was defined as failure of the stent to be either delivered to or adequately deployed at the target lesion site. Clinical records and angiograms were reviewed and qualitative coronary angiography was performed for all cases of failed deployment. Deployment was unsuccessful in 108 (8.3%) cases involving 134 stents. Stenting was attempted as a primary procedure in 40%, as bailout in 18%, and for suboptimal angioplasty in 43% of cases. In 87% of cases, attempts were made to withdraw the stent from the coronary artery. Stent retrieval was successful in 45%, peripheral embolization occurred in 38% of patients, and in 4% the stent dislodged in the left main artery. In 35% of cases, additional stent(s) were successfully deployed. Deployment failure was associated with an overall in-hospital adverse outcome in 19% of patients, including 16% urgent coronary artery bypass grafting, 5% nonfatal myocardial infarction, and 3 in-hospital deaths. At 6-month follow-up, 39% of patients had had at least 1 adverse clinical outcome of death, myocardial infarction, or repeat target lesion revascularization. CONCLUSIONS Failure to deploy stents is a serious and relatively common problem that is associated with significant morbidity and mortality rates. Improved deployment strategies, including new stent designs, are required to improve procedural outcomes.
Circulation-cardiovascular Interventions | 2009
Clare E. Appleby; Joan Ivanov; Shahar Lavi; Karen Mackie; Eric Horlick; Douglas Ing; Christopher B. Overgaard; Peter H. Seidelin; Rüdiger von Harsdorf; Vladimir Dzavik
Background—An observational study determining the long-term impact of chronic kidney disease (CKD) on patients undergoing percutaneous coronary intervention at a tertiary cardiac referral center. CKD is associated with poor in-hospital outcomes after percutaneous coronary intervention, but its effect beyond 1 year, particularly in the drug-eluting stent (DES) era, has not been reported. Methods and Results—Baseline creatinine was available for 11 953 patients entered into a prospective registry (April 2000 to September 2007). Patients were stratified: those with or without at least moderate CKD (creatinine clearance, <60 mL/min). Follow-up data were obtained through linkage to a provincial registry. Kaplan–Meier analysis was performed. Cox multiple-regression analysis identified independent predictors of late mortality and major adverse cardiac events (MACE) and examined the association between DES use and late outcomes in the presence or absence of CKD. CKD was present in 3070 patients (25.7%). In-hospital mortality and MACE were significantly increased in CKD (3.34% versus 0.44%, P<0.001 and 5.73% versus 2.2%, P<0.001). Survival and MACE-free survival at 7 years were reduced (64.5±1.4% versus 89.4±0.5%, P<0.001; 44.0±1.4% versus 63.4±0.8%, P<0.001). CKD was an independent predictor of late mortality and MACE (hazard ratio [HR]: 2.18, CI: 1.90 to 2.49, P<0.0001; HR: 1.37, CI: 1.25 to 1.49, P<0.0001). DES use was associated with a significant reduction in both (HR: 0.71, CI: 0.60 to 0.83, P<0.0001; HR: 0.70, CI: 0.63 to 0.78, P<0.0001). In patients with CKD, DES use was associated with reduced revascularization (HR: 0.68, CI: 0.53 to 0.88, P=0.004) and reduced MACE (HR: 0.81, CI: 0.69 to 0.95, P=0.011) but not reduced mortality (HR: 0.85, CI: 0.69 to 1.05, P=0.1). Conclusion—In a large registry of “all comers” for percutaneous coronary intervention, CKD was an independent predictor of adverse late outcomes. DES use may be associated with improved long-term outcomes in this high-risk cohort, but further prospective studies are required.
American Heart Journal | 2009
Saqib Chowdhary; Joan Ivanov; Karen Mackie; Peter H. Seidelin; Vladimír Džavík
BACKGROUND Benchmarking the performance of providers is an increasing priority in many health care economies. In-hospital mortality represents an important and uniformly assessed measure on which to examine the outcome of percutaneous coronary intervention (PCI). Most existing prediction models of in-hospital mortality after PCI were derived from 1990s data, and their current relevance is uncertain. METHODS From consecutive PCIs performed during 2000-2008, derivation and validation cohorts of 10,694 and 5,347 patients, respectively, were analyzed. Logistic regression for in-hospital death yielded integer risk weights for each independent predictor variable. These were summed for each patient to create the Toronto PCI risk score. RESULTS Death occurred in 1.3% of patients. Independent predictors with associated risk weights in parentheses were as follows: age 40 to 49 y (1), 50 to 59 y (2), 60 to 69 y (3), 70 to 79 y (4), and > or =80 y (5); diabetes (2); renal insufficiency (2); New York Heart Association class 4 (3); left ventricular ejection fraction <20% (3); myocardial infarction in the previous month (3); multivessel disease (1); left main disease (2); rescue or facilitated PCI (3); primary PCI (4); and shock (6). The model had a receiver operator curve of 0.96 and Hosmer-Lemeshow goodness-of-fit P = .16 in the validation set. Four previously published external models were tested in the entire data set. Three models had ROC curves significantly less than the Toronto PCI score, and all 4 showed significant levels of imprecision. CONCLUSIONS The Toronto PCI mortality score is an accurate and contemporary predictive tool that permits evaluation of risk-stratified outcomes and aids counseling of patients undergoing PCI.
American Journal of Cardiology | 2008
Mark Osten; Joan Ivanov; Jonas Eichhöfer; Peter H. Seidelin; John R. Ross; Alan Barolet; Eric Horlick; Douglas Ing; Leonard Schwartz; Karen Mackie; Vladimír Džavík
Patients with chronic renal insufficiency (RI) have higher in-hospital mortality and major adverse cardiac event (MACE) rates after percutaneous coronary intervention (PCI). The mechanisms of this adverse course are not well understood. It was hypothesized that this worse outcome may be caused by inadequate PCI results secondary to more complex coronary anatomy in patients with RI. Baseline, procedural, and outcome variables of all PCI cases at the University Health Network are entered prospectively in the PCI Registry. All PCI cases between April 1, 2000, and October 31, 2005, excluding patients in shock, who had preprocedural creatinine clearance (CrCl) measured were included in this study (n = 10,821 of 11,023 patients). Moderate RI (CrCl <60 ml/min) was evaluated as an independent predictor of procedural outcomes, death, and MACE (defined as death, myocardial infarction, abrupt closure, or coronary artery bypass grafting). Moderate RI (CrCl <60 ml/min) independently predicted the procedural outcomes of worse residual stenosis >20% (p = 0.03), number of undeliverable stents (p = 0.003), and smallest stent diameter (p <0.001). Worst residual stenosis >20% and any undeliverable stent were significantly associated with in-hospital MACEs (odds ratio [OR] 3.97, 95% confidence interval [CI] 3.0 to 5.3, p <0.001 and OR 1.89, 95% CI 1.2 to 2.9, p = 0.002) and mortality (OR 3.82, 95% CI 2.2 to 6.7, p <0.001 and OR 3.0, 95% CI 1.6 to 5.9, p = 0.002). These risks were independent of all other measured variables. In conclusion, moderate to severe RI was a strong predictor of worse procedural results during PCI, which, in turn, were independent predictors of in-hospital MACE and mortality and independent contributors to the higher risk of in-hospital adverse events observed after PCI in patients with RI.
American Heart Journal | 2008
Christopher B. Overgaard; Joan Ivanov; Peter H. Seidelin; Mina Todorov; Karen Mackie; Vladimír Džavík
BACKGROUND Thrombocytopenia (TP) is a common baseline abnormality in patients undergoing percutaneous coronary intervention (PCI). Whether TP has any influence on the outcome of PCI patients is unknown. Our aim was to determine if TP at baseline impacts on inhospital mortality in patients undergoing PCI at our institution. METHODS From April 2000 until October 2005, 11,021 PCI procedures were performed at the University Health Network in Toronto, Canada. Baseline platelet count was recorded in 10,821 (98.2%) cases. Patients with platelets <150 x 10(9)/L were assigned to the TP group (n = 639), and those with > or =150 x 10(9)/L to the normal platelet group (n = 10,182). Clinical, angiographic, procedural, and inhospital outcome data were collected prospectively. Multivariable analysis was performed using logistic regression. RESULTS In-hospital death rate was higher in the TP group (1.9% vs 0.6%, P < .001) due to an increased mortality in TP patients undergoing urgent (3.55% vs 1.15%, P < .001) but not elective (0% vs 0.04%, P = 1.0) PCI. Major bleeding (1.7% vs 0.8%, P < .05) and gastrointestinal bleeding (1.1% vs 0.5%, P < .05) complications were greater in the TP group. Multivariate analysis demonstrated that baseline TP was an independent predictor of inhospital mortality (odds ratio 2.07 [1.1-4.1], P = .035). CONCLUSIONS Baseline TP is an independent predictor of inhospital mortality in patients undergoing PCI for urgent indications. Thrombocytopenia should be considered an important addition to PCI risk prediction models to improve their precision and clinical applicability.
American Journal of Cardiology | 2008
Nicholas Collins; Peter H. Seidelin; Paul Daly; Joan Ivanov; Alan Barolet; Karen Mackie; Sanh Bui; Leonard Schwartz; Vladimír Džavík
The optimal approach to percutaneous coronary intervention (PCI) of bifurcation lesions remains unclear, reflecting lack of long-term follow-up and heterogeneity of lesions encountered. We evaluated the long-term outcome of patients undergoing bifurcation PCI followed in the prospective bifurcation registry at the University Health Network, Toronto, Ontario, Canada. Of 526 patients undergoing bifurcation PCI between November 2003 and March 2005, most (n = 406) were treated by main vessel stenting only (n = 266) or crush/culotte stenting (n = 140). After median follow-up of 26.5 months, major adverse cardiac events (MACEs) and Canadian Cardiovascular Society class > or =2 angina occurred in 28.5% and 22.3% of patients in these groups, respectively (p = 0.190), whereas MACE rates were 20.8% for main vessel stenting and 18.7% for crush/culotte stenting (p = 0.670). A low bifurcation angle was associated with better outcomes in the crush/culotte group but had no effect on outcome of patients treated with main vessel stenting only. Use of crush/culotte techniques independently predicted freedom from MACEs or Canadian Cardiovascular Society class > or =2 angina compared with main vessel stenting only (odds ratio 0.55, 95% confidence interval 0.32 to 0.94, p = 0.029). In conclusion, the use of crush/culotte stenting is safe, with efficacy and MACE rates being similar to main vessel stenting alone. Our observations regarding the effect of lesion characteristics such as bifurcation angle and extent of side branch disease on outcome underscore the need for randomized trials that are inclusive of patients with complex side branch disease.
Canadian Journal of Cardiology | 2013
Kay W. Ho; Joan Ivanov; Xavier Freixa; Christopher B. Overgaard; Mark Osten; Douglas Ing; Eric Horlick; Karen Mackie; Peter H. Seidelin; Vladimír Džavík
BACKGROUND The safety and efficacy of triple therapy (TT; warfarin with dual antiplatelet therapy [DAPT]) in post-percutaneous coronary intervention (PCI) patients with atrial fibrillation (AF) are unclear. We aimed to determine whether TT is associated with a decreased stroke rate and an acceptable bleeding rate in this population. METHODS This was a single-centre, retrospective study. Primary composite outcome was death, ischemic stroke, or transient ischemic attack. Secondary outcomes included components of primary outcome, bleeding, and blood transfusion rates. RESULTS Of 602 post-PCI patients with AF between 2000 and 2009, 382 received TT, 220 DAPT. Mean follow-up post PCI was 5.9 ± 5.0 months. The TT group had a higher CHADS(2) score (2.6 vs 2.1, P < 0.001), older age (72.9 vs 70.5 years, P = 0.039), more heart failure (72.3% vs 36.9%, P = 0.010), and more strokes (14.4% vs 6.4%, P = 0.010). Neither primary outcome, major bleeding, nor blood transfusion rates differed between treatment groups, but more gastrointestinal bleeding occurred with TT use (2.6% vs 0.5%, P = 0.045). Net clinical benefit was -5.2 (CHADS(2) ≤ 2), 0.9 (CHADS(2) > 2), and -3.2 (overall) per 100 patient-years. CONCLUSIONS Although we found no association with TT usage and a reduction in cerebrovascular ischemic or major bleeding events in post-PCI patients with AF regardless of CHADS(2) score vs DAPT, the study was likely underpowered to demonstrate a clinically relevant reduction. TT was associated with a 5-fold increase in gastrointestinal bleeding vs DAPT. Net clinical benefit calculations suggest benefits of TT in patients with CHADS(2) > 2. Stratification with CHADS(2) might be useful to determine the optimal antithrombotic therapy post PCI.
Catheterization and Cardiovascular Interventions | 2011
Clare E. Appleby; Joan Ivanov; Karen Mackie; Vladimír Džavík; Christopher B. Overgaard
Objective: To compare in‐hospital outcomes of a large cohort of very elderly patients (age ≥85 years) with younger patients (age <85 years) undergoing percutaneous coronary intervention (PCI) for all indications at our institution. Background: Interventionist cardiologists are often reluctant to undertake PCI in very elderly patients due to the perception of poor outcome in this high‐risk cohort. However, the prognostic significance of advanced age itself is not clear. Methods: Baseline clinical, angiographic and procedural variables, and in‐hospital outcome data were entered into a prospective registry of 17,572 consecutive patients undergoing PCI at the University Health Network between April 2000 and December 2008. Patients were stratified according to age (<85 years, n = 17,168, or ≥85 years, n = 404) and in‐hospital mortality, major adverse cardiac events (MACE), and complication rates were calculated. Logistic regression‐analysis identified independent predictors of unadjusted mortality and MACE. Very elderly patients were propensity matched with younger patients (1:2 ratio), and the analysis repeated. Results: Very elderly patients had a mean age of 87.5 ± 2.9 (range, 85–97 years) vs. 62.8 ± 11.1 years for the younger cohort and had a greater number of comorbid conditions. This cohort were more likely to present as an urgent or primary PCI, underwent more complex interventions, and achieved less angiographic success. Unadjusted mortality and post procedure myocardial infarction were significantly higher in very elderly patients (6.93% vs. 1.20%, P < 0.0001 and 4.46% vs. 2.74%, P = 0.04). Renal, neurological, and access‐site complications were all greater in the very elderly cohort. Although age ≥85 years was a significant independent predictor of both mortality (OR, 2.62; CI, 1.44–4.78, P = 0.0016) and MACE (OR, 1.94; CI, 1.25–3.01, P = 0.003), other variables such as cardiogenic shock were more potent predictors of adverse outcomes. Conclusion: Very elderly patients represent a high‐risk cohort, with significantly increased in‐hospital mortality and complication rates after PCI. Death occurred predominantly in very elderly patients undergoing nonelective PCI. Decisions to proceed with PCI in very elderly patients should be based on other prognostic variables in combination with advanced age, and these patients should not be excluded from revascularization based on age alone.
Catheterization and Cardiovascular Interventions | 2009
Shahar Lavi; Joan Ivanov; Clare E. Appleby; Peter H. Seidelin; Karen Mackie; Leonard Schwartz; Vladimír Džavík
Objectives: To report on outcomes with selective use of embolic protection devices (EPD) during percutaneous coronary intervention (PCI) to saphenous vein grafts (SVG). Background: PCI to SVG is associated with increased risk and the use of EPD is recommended in this setting. Methods: Angiographic and clinical outcomes were prospectively obtained from 534 consecutive patients who underwent PCI to SVG with or without EPD at a tertiary cardiac centre. Long‐term outcomes were obtained by linkage to a provincial registry. Results: EPD, deployed in 198 of 373 SVGs (53%) suitable for deployment of a distal EPD, were used more often in ectatic (33% vs. 19%, P = 0.003), ulcerated (17% vs. 9%, P = 0.03), thrombotic (26% vs. 10%, P < 0.0001) vein grafts, with longer degenerated segments (P = 0.002), and in lesions involving the body of the graft (85% vs. 66%, P < 0.0001), and less with lesions involving the graft ostium (29% vs. 44%, P = 0.003). Patients suitable for but not receiving EPD tended to be more likely to have a periprocedural myocardial infarction. During 3 years of follow‐up, 49% of the patients had a cardiovascular event. Cumulative mortality was 8.4%, 18.8% and 14.7% in patients unsuitable for distal EPD, suitable but without EPD, and with EPD (p = 0.11). Nonuse of EPD was an independent predictor of MACE at 3 years. (P = 0.02). Conclusions: Selective use of EPD is associated with low in‐hospital cardiovascular event rates. Long‐term outcomes are manifested by a high rate of events, especially in patients with SVGs suitable for but not receiving EPD. This suggests that routine use of distal EPD may be warranted in unselected patients with suitable SVG anatomy.