Matthew Sibbald

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

BACKGROUNDnRadial 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.nnnMETHODSnUsing 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.nnnRESULTSnMean 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).nnnCONCLUSIONSnWrist 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.

Severe hemolysis associated with use of the impella LP 2.5 mechanical assist device

The Impella LP 2.5 is a percutaneously implantable axial flow device designed to offer circulatory support for patients in cardiogenic shock during percutaneous coronary interventions (PCI). While most axial flow devices are associated with hemolysis, clinically relevant hemolysis with this device has not been reported. We report a case of a 66‐year‐old woman with hemodynamic collapse during an elective PCI who was successfully resuscitated with an Impella device. She developed marked biochemical evidence of intravascular hemolysis. This necessitated device removal which resulted in prompt resolution of the hemolysis. We advise routine measurement of biochemical markers of hemolysis and serial hemoglobin values during Impella device support to allow timely detection and treatment of this important complication.

Association between drug-eluting stent type and clinical outcomes in patients with chronic kidney disease undergoing percutaneous coronary intervention.

BACKGROUNDnThe comparative efficacy of first- vs second-generation drug-eluting stents (DESs) in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI) is unknown.nnnMETHODSnA retrospective analysis of consecutive patients undergoing PCI at a tertiary PCI center from 2007-2011 was performed, with linkage to administrative databases for long-term outcomes. CKD was defined as creatinine clearance (CrCl) < 60 mL/min. Propensity matching by multivariable scoring method and Kaplan-Meier analyses were performed.nnnRESULTSnOf 6481 patients with available CrCl values undergoing a first PCI during the study period, 1658 (25%) had CKD. First- and second-generation DESs were implanted in 320 (19.3%) and 128 (7.7%) patients with CKD, respectively. At 2 years, no significant differences were observed between first-generation (nxa0= 126) and second-generation (nxa0= 126) propensity-matched DES cohorts for the outcomes of death (19% vs 16%; Pxa0= 0.51), repeat revascularization (10% vs 10%; Pxa0= 1.00), and major adverse cardiovascular and cerebrovascular events (MACCE) (36% vs 37%; Pxa0= 0.90). The 2-year Kaplan-Meier survival was also similar (Pxa0= 0.77). In patients with CKD, second-generation DES type was not an independent predictor for death (Pxa0= 0.49) or MACCE (Pxa0= 1.00).nnnCONCLUSIONSnAlthough the use of first- and second-generation DESs was associated with similar 2-year safety and efficacy in patients with CKD, our results cannot rule out a beneficial effect of second- vs first-generation DESs owing to small sample size. Future studies with larger numbers of patients with CKD are needed to identify optimal stent types, which may improve long-term clinical outcomes.

Electrocardiographic Interpretation Skills of Cardiology Residents: Are They Competent?

Achieving competency at electrocardiogram (ECG) interpretation among cardiology subspecialty residents has traditionally focused on interpreting a target number of ECGs during training. However, there is little evidence to support this approach. Further, there are no data documenting the competency of ECG interpretation skills among cardiology residents, who become de facto the gold standard in their practice communities. We tested 29 Cardiology residents from all 3 years in a large training program using a set of 20 ECGs collected from a community cardiology practice over a 1-month period. Residents interpreted half of the ECGs using a standard analytic framework, and half using their own approach. Residents were scored on the number of correct and incorrect diagnoses listed. Overall diagnostic accuracy was 58%. Of 6 potentially life-threatening diagnoses, residents missed 36% (123 of 348) including hyperkalemia (81%), long QT (52%), complete heart block (35%), and ventricular tachycardia (19%). Residents provided additional inappropriate diagnoses on 238 ECGs (41%). Diagnostic accuracy was similar between ECGs interpreted using an analytic framework vs ECGs interpreted without an analytic framework (59% vs 58%; F(1,1333) = 0.26; P = 0.61). Cardiology resident proficiency at ECG interpretation is suboptimal. Despite the use of an analytic framework, there remain significant deficiencies in ECG interpretation among Cardiology residents. A more systematic method of addressing these important learning gaps is urgently needed.

Long-term Outcome of Unprotected Left Main Stenting: A Canadian Tertiary Care Experience

BACKGROUNDnCoronary stenting is increasingly used to treat unprotected left main disease in selected patients. However, there is a paucity of data on the long-term outcome of these patients in a Canadian context outside of clinical trials.nnnMETHODSnWe retrospectively reviewed all provincially-insured patients undergoing left main coronary stenting at a large tertiary referral centre from 2000-2011. Pre-procedural angiograms were reviewed to identify the location of left main disease, and extent of concomitant coronary disease quantified by calculating Synergy Between Percutaneous Coronary Intervention With TAXUS Drug-Eluting Stent and Cardiac Surgery (SYNTAX) scores for each patient. In-hospital death and major adverse cardiac event (MACE) rates were evaluated as were long-term death and MACE rates obtained via linkage of our institutional registry with the Ontario health claims database.nnnRESULTSnTwo hundred twenty-one patients underwent unprotected left main stenting with 29 (13.1%) in-hospital death and 34 (15.4%) a MACE. At an average follow-up of 3.1 ± 2.8 years, 109 patients (49.3%) died and 151 (68.3%) experienced a MACE. Higher SYNTAX tertile and use of bare metal rather than drug-eluting stents was associated with increased rates of in-hospital and long-term death.nnnCONCLUSIONSnThis study reports, to our knowledge, the largest Canadian cohort of unprotected left main stenting over more than a decade. Coronary stenting was associated with acceptable in-hospital event rates, but poor long-term outcomes, reflecting the higher-risk population traditionally selected for this procedure.

Can diagnostic and procedural skills required to practice cardiology as a specialist be mastered in 3 years

Cognitive and procedural skills required of cardiologists have increased in the past 10 years. What is unknown is whether residents consistently meet recommended volumes during training and what their own subjective assessments of their competency are after training. The purpose of this study was to (1) determine whether current training provides residents with opportunities to develop skills to function independently and (2) identify whether residents perceive gaps in their skills. We surveyed current and recent graduates of adult cardiology programs in Canada. One hundred ten responses from 425 surveys were received. Procedural and diagnostic test interpretation volumes were recorded, as were the optimum number the respondents believed were important to complete to function independently. These volumes were compared with the 2008 American College of Cardiology Core Cardiology Training Symposium (COCATS 3) and the Canadian Cardiovascular Society (CCS) recommendations for training. The proportion of residents meeting recommended volumes for diagnostic test interpretation ranged from 7% (Holter monitors) to 91% (echocardiograms). For procedures, the range was from 71% (echocardiography) to 100% (cardioversion). The ratio of residents perceived minimum numbers believed to be required for proficiency for diagnostic test interpretation to those recommended ranged from 14% (electrocardiograms) to 116% (echocardiograms), and for procedures, the ratio was 66% (temporary pacemaker placement) to 116% (echocardiography). Recent graduates perception of minimum required numbers to achieve competency is underestimated compared with COCATS 3 and CCS recommendations. Few graduates achieved the recommended volume targets suggested for diagnostic test interpretation.