Peter H. Seidelin

Decreased complication rates using the transradial compared to the transfemoral approach in percutaneous coronary intervention in the era of routine stenting and glycoprotein platelet IIb/IIIa inhibitor use: A large single-center experience

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.

Predictors of angiographic restenosis after coronary intervention in patients with diabetes mellitus.

BACKGROUND Patients with diabetes mellitus are particularly prone to restenosis after percutaneous coronary intervention. An exploratory, nested, case-control study was undertaken to identify clinical, lesional, and procedural predictors of angiographic restenosis in these patients. METHODS Seventy-five patients with diabetes mellitus with 86 coronary lesions were selected from a larger population of 217 patients who had undergone 6-month angiographic follow-up after a first, successful balloon angioplasty (PTCA) or stent implantation procedure. Data collection was by patient interview and review of hospital database and other medical records. All angiograms were analyzed with quantitative coronary angiography, and restenosis was defined as a >or=50% diameter reduction at the treated site. A multivariate analysis of 10 prespecified explanatory variables, derived from a literature review, was performed on a per-lesion basis. RESULTS There were 45 patients (53 lesions) with restenosis and 30 patients (33 lesions) without restenosis. Univariate predictors of binary restenosis were periprocedural glycosylated hemoglobin level, vessel reference diameter, PTCA, and larger final balloon size to reference artery diameter ratio. Multiple logistic regression identified poor glycemic control (odds ratio [OR] 3.03, 95% CI 1.06-8.65, P =.038), small vessel reference diameter (OR 3.41, 95% CI 1.17-9.95, P =.025), and mode of intervention (OR 3.12, 95% CI 1.08-9.00, P =.036) as independent risk factors. Vessel reference diameter appeared to be an important effect modifier of the association between type of intervention and angiographic outcome, with stenting no longer superior to PTCA in patients with diabetes mellitus who had vessels <2.87 mm in diameter (P =.054). CONCLUSION Poor glycemic control, vessel size, and PTCA were independent predictors of restenosis in patients with diabetes mellitus. It is possible that improved periprocedural glycemic control, in addition to stenting, may reduce the restenosis rate in these patients.

The Adverse Long-Term Impact of Renal Impairment in Patients Undergoing Percutaneous Coronary Intervention in the Drug-Eluting Stent Era

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.

The Toronto score for in-hospital mortality after percutaneous coronary interventions.

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.

Impact of renal insufficiency on angiographic, procedural, and in-hospital outcomes following percutaneous coronary intervention.

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.

Thrombocytopenia at baseline is a predictor of inhospital mortality in patients undergoing percutaneous coronary intervention

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.

Long-Term Outcomes After Percutaneous Coronary Intervention of Bifurcation Narrowings

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.

Antithrombotic Therapy After Coronary Stenting in Patients With Nonvalvular Atrial Fibrillation

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.

Predictors of Radial Artery Size in Patients Undergoing Cardiac Catheterization: Insights From the Good Radial Artery Size Prediction (GRASP) Study

BACKGROUND Radial artery occlusion occurs after transradial cardiac catheterization or percutaneous coronary intervention. Although use of a sheath larger than the artery is a risk factor for radial artery occlusion, radial artery size is not routinely measured. We aimed to identify bedside predictors of radial artery diameter. METHODS Using ultrasound, we prospectively measured radial, ulnar, and brachial artery diameters of 130 patients who presented for elective percutaneous coronary intervention or diagnostic angiography. Using prespecified candidate variables we used multivariable linear regression to identify predictors of radial artery diameter. RESULTS Mean internal diameters of the right radial, ulnar, and brachial arteries were 2.44 ± 0.60, 2.14 ± 0.53, and 4.50 ± 0.88 mm, respectively. Results for the left arm were similar. The right radial artery was larger in men than in women (2.59 vs 1.91 mm; P < 0.001) and smaller in patients of South Asian descent (2.00 vs 2.52 mm; P < 0.001). Radial artery diameter correlated with wrist circumference (r(2) = 0.26; P < 0.001) and shoe size (r(2) = 0.25; P < 0.001) and weakly correlated with height (r(2) = 0.14; P < 0.001), weight (r(2) = 0.18; P < 0.001), body mass index (r(2) = 0.07; P = 0.002), and body surface area (r(2) = 0.22; P < 0.001). The independent predictors of a larger radial artery were wrist circumference (r(2) = 0.26; P < 0.001), male sex (r(2) = 0.06; P < 0.001), and non-South Asian ancestry (r(2) = 0.05; P = 0.006; final model r(2) = 0.37; P < 0.001). A risk score using these variables predicted radial artery diameter (c-statistic, 0.71). CONCLUSIONS Wrist circumference, male sex, and non-South Asian ancestry are independent predictors of increased radial artery diameter. A risk score using these variables can identify patients with small radial arteries.

Effect of operator and institutional volume on clinical outcomes after percutaneous coronary interventions performed in Canada and the United States: a brief report from the Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) study.

BACKGROUND The Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial compared the use of eptifibatide with placebo in 2064 coronary intervention patients. It was previously reported that Canadian patients had reduced rates of 30-day and one-year death, myocardial infarction (MI) or target vessel revascularization (TVR) compared with patients in the United States (US). OBJECTIVE To examine whether operator or institutional volume differences explain the regional variation in clinical outcome. METHODS AND RESULTS Each site received an operator and institutional volume survey. Fifty-seven sites (62%) returned complete data on 1338 patients. In this smaller cohort, Canadian patients had reduced rates of 30-day and one-year death, MI or TVR compared with US patients (6.3% versus 10.3% and 14.9% versus 20.1%, respectively; P<0.05 for both comparisons). Among 176 physicians with a median of 13 years experience, the median operator volume was 200 cases per year. Operators with fewer than 100 cases per year had higher rates of 30-day death, MI or TVR (13.2% versus 8.7%; P=0.18) and large MI (7.7% versus 3.3%; P=0.06) than those with 100 or more cases per year. The median institutional volume was 1064 cases per year. Canadian and US centres had similar operator and institutional volumes. By multivariate modelling, operator volume was not predictive of adverse clinical events. However, the rates of 30-day and one-year death, MI or TVR fell by 3% for every 100 patients treated by the institution (OR 0.97; P=0.058 and P=0.002, respectively). Enrollment in Canada was associated with improved outcomes at 30 days (OR 0.50; P=0.001) and one year (OR 0.66; P=0.001) despite inclusion of volume variables in the models. CONCLUSIONS In the ESPRIT study, institutional volume was associated with a modest reduction in risk of death, MI or TVR over short- and long-term follow-up periods. The Canadian and US investigators and institutions selected in ESPRIT had similar annual procedural volumes. Therefore, volume variables did not explain the differential risk of clinical events observed for patients enrolled in the two countries.