Adjunctive Bare-Metal Stenting Associated With Improved Outcomes in Patients With Multivessel Disease Treated With Drug-Eluting Stents.

BACKGROUND: The use of both bare-metal stents (BMSs) and drug-eluting stents (DESs) in the setting of multivessel percutaneous coronary intervention (PCI) continues because of cost considerations. METHODS: A retrospective analysis of patients with ≥ 2 coronary arteries with angiographic stenoses of ≥ 70% severity who were treated with multivessel PCI and ≥ 2 stents between April 2007 and March 2011 was performed using a prospective single-centre PCI registry. Follow-up data were obtained from the Discharge Abstract Database of the Canadian Institute for Health Information and the Registered Persons Database. We performed propensity matching of the DES + BMS and DES-only groups, as well as Cox multiple regression analyses to determine the independent predictors of adverse events. RESULTS: A total of 1299 patients (514 in the DES + BMS group and 785 in the DES group) fulfilled the study criteria. Death or repeated revascularization at 5 years occurred less frequently in the DES + BMS group than in the DES group (23.9% ± 2.6% vs 33.1% ± 2.4%; P = 0.01), and major adverse cardiac events (MACE) tended to be less common in the DES + BMS group (31.1% ± 3.0% vs 36.7% ± 2.4%; P = 0.056). Kaplan-Meier estimates revealed an adjusted benefit with the DES + BMS strategy for death (11.4 ± 2.9 vs 14.9 ± 2.8; P = 0.035) and for death and repeated revascularization (25.6 ± 3.5 vs 32.4 ± 3.4; P = 0.034). CONCLUSIONS: A DES + BMS PCI strategy is associated with a lower incidence of repeated revascularization and MACE at 5-year follow up. For patients undergoing multivessel PCI who have favourable anatomy and clinical features, a combined approach using DES and BMS appears to be a viable option for contemporary PCI practice.

Clinical outcomes of treatment by percutaneous coronary intervention versus coronary artery bypass graft surgery in patients with chronic kidney disease undergoing index revascularization in Ontario.

BACKGROUND: There is a paucity of data on the comparative effectiveness of percutaneous coronary intervention using contemporary drug-eluting stent (DES) compared with coronary artery bypass graft (CABG) surgery in patients with chronic kidney disease. METHODS AND RESULTS: A population-based study was performed using the Cardiac Care Network, a provincial registry of all patients undergoing cardiac catheterization in Ontario, to evaluate patients treated with either percutaneous coronary intervention using DES or CABG between October 1, 2008, and September 30, 2011. Chronic kidney disease was defined as creatinine clearance <60 mL/min. A total of 1786 propensity-matched patients from 4006 patients with chronic kidney disease undergoing index revascularization for multivessel disease with either DES or isolated CABG (n=893 each group) were analyzed. Baseline and procedural characteristics between percutaneous coronary intervention and CABG groups were well-balanced, including urgent revascularization priority, diabetes mellitus, left ventricular function, and 3-vessel disease. The 1-, 2-, and 3-year Kaplan-Meier survival analyses in propensity-matched patients favored CABG (93.2% versus 89.3%; 86.6% versus 80.3%; 80.8% versus 71.5%, respectively; P<0.001). The CABG cohort had greater 1-, 2-, and 3-year freedom from major adverse cardiac and cerebrovascular events (89.4% versus 71.2%; 81.9% versus 60.5%; 75.2% versus 51.8%, respectively; P<0.001). Cox regression analysis identified DES use to be associated with greater hazard for late mortality (hazard ratio, 1.58; 95% confidence interval, 1.32-1.90) and major adverse cardiac and cerebrovascular events (2.62; 2.28-3.01; all P<0.001). CONCLUSIONS: In this large provincial registry, CABG was associated with improved early and late clinical outcomes when compared with percutaneous coronary intervention using DES in patients with chronic kidney disease undergoing index revascularization.

Increasing mortality burden among adults with complex congenital heart disease.

BACKGROUND: Progress in management of congenital heart disease has shifted mortality largely to adulthood. However, adult survivors with complex congenital heart disease are not cured and remain at risk of premature death as young adults. Thus, our aim was to describe the evolution and mortality risk of adult patient cohorts with complex congenital heart disease. METHODS: Among 12,644 adults with congenital heart disease followed at a single center from 1980 to 2009, 176 had Eisenmenger syndrome, 76 had unrepaired cyanotic defects, 221 had atrial switch operations for transposition of the great arteries, 158 had congenitally corrected transposition of the great arteries, 227 had Fontan palliation, and 789 had repaired tetralogy of Fallot. We depict the 30-year evolution of these 6 patient cohorts, analyze survival probabilities in adulthood, and predict future number of deaths through 2029. RESULTS: Since 1980, there has been a steady increase in numbers of patients followed, except in cohorts with Eisenmenger syndrome and unrepaired cyanotic defects. Between 1980 and 2009, 308 patients in the study cohorts (19%) died. At the end of 2009, 85% of survivors were younger than 50 years. Survival estimates for all cohorts were markedly lower than for the general population, with important differences between cohorts. Over the upcoming two decades, we predict a substantial increase in numbers of deaths among young adults with subaortic right ventricles, Fontan palliation, and repaired tetralogy of Fallot. CONCLUSIONS: Anticipatory action is needed to prepare clinical services for increasing numbers of young adults at risk of dying from complex congenital heart disease.

Rotational atherectomy through the radial artery is associated with similar procedural success when compared with the transfemoral route.

OBJECTIVES: Rotational atherectomy (RA) has traditionally been carried out using 7 or 8 Fr guides through a transfemoral approach to allow for passage of 2.0 mm burrs or larger. With transradial percutaneous coronary intervention becoming more common, our aim was to investigate whether transradial RA would offer equivalent rates of procedural success when compared with transfemoral RA. METHODS: Using a prospective percutaneous coronary intervention registry, we identified all patients who had undergone RA at the University Health Network between January 2001 and December 2012 and compared those in whom the transfemoral approach had been used with those in whom the transradial approach had been used. RESULTS: A total of 119 patients were analyzed (67 femoral, 52 radial). Larger guides were used in the femoral group compared with the radial group (6.79 vs. 6.31 Fr, P<0.001), but there was no significant difference in the number of burrs used or the average size of the burrs. There was no significant difference in the procedural success rate (91 vs. 96%, P=0.46), fluoroscopy time (40.5 vs. 43.8 min, P=0.37), radiation dose (27743 vs. 29939 cGy cm, P=0.50), or contrast use (429 vs. 384 ml, P=0.19) between the two groups. Patients in the femoral group were more likely to have a transvenous pacing wire inserted (25 vs. 6%, P=0.006). Access site crossover tended to occur more frequently in the radial group (6 vs. 0%, P=0.08). CONCLUSION: We have shown that RA through the transradial route is associated with outcomes similar to those achieved through the transfemoral route. Keeping in mind the single-center context and the small number of operators, our data do not suggest an increased rate of failure of RA through the radial route despite the use of smaller guiding catheters.

Long-term outcome of unprotected left main stenting: a Canadian tertiary care experience.

BACKGROUND: Coronary 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. METHODS: We 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. RESULTS: Two 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. CONCLUSIONS: This 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.

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

BACKGROUND: The 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. METHODS: A 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. RESULTS: Of 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 (n = 126) and second-generation (n = 126) propensity-matched DES cohorts for the outcomes of death (19% vs 16%; P = 0.51), repeat revascularization (10% vs 10%; P = 1.00), and major adverse cardiovascular and cerebrovascular events (MACCE) (36% vs 37%; P = 0.90). The 2-year Kaplan-Meier survival was also similar (P = 0.77). In patients with CKD, second-generation DES type was not an independent predictor for death (P = 0.49) or MACCE (P = 1.00). CONCLUSIONS: Although 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.

Dysphagia and associated risk factors following extubation in cardiovascular surgical patients.

Following cardiovascular (CV) surgery, prolonged mechanical ventilation of >48 h increases dysphagia frequency over tenfold: 51 % compared to 3-4 % across all durations. Our primary objective was to identify dysphagia frequency following CV surgery with respect to intubation duration. Our secondary objective was to explore characteristics associated with dysphagia across the entire sample. Using a retrospective design, we stratified all consecutive patients who underwent CV surgery in 2009 at our institution into intubation duration groups defined a priori: I (≤ 12 h), II (>12 to ≤ 24 h), III (>24 to ≤ 48 h), and IV (>48 h). Eligible patients were >18 years old who survived extubation following coronary artery bypass alone or cardiac valve surgery. Patients who underwent tracheotomy were excluded. Pre-, peri-, and postoperative patient variables were extracted from a pre-existing database and medical charts by two blinded reviewers. Disagreements were resolved by consensus. Across the entire sample, multivariable logistic regression analysis determined independent predictors of dysphagia. Across the entire sample, dysphagia frequency was 5.6 % (51/909) but varied by group: I, 1 % (7/699); II, 8.2 % (11/134); III, 16.7 % (6/36); and IV, 67.5 % (27/40). Across the entire sample, the independent predictors of dysphagia included intubation duration in 12-h increments (p < 0.001; odds ratio [OR] 1.93, 95 % confidence interval [CI] 1.63-2.29) and age in 10-year increments (p = 0.004; OR 2.12, 95 % CI 1.27-3.52). Patients had a twofold increase in their odds of developing dysphagia for every additional 12 h with endotracheal intubation and for every additional decade in age. These patients should undergo post-extubation swallow assessments to minimize complications.

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.

Sex differences in the management and outcomes of Ontario patients with cardiogenic shock complicating acute myocardial infarction.

BACKGROUND: Sex differences in the management of acute myocardial infarction (AMI) patients with cardiogenic shock (CS) have not been well studied. METHODS: We examined mortality and revascularization rates of 9750 patients with CS between 1992 and 2008 in the Ontario Myocardial Infarction Database. Men and women were compared in the entire cohort and in subgroups divided by age (aged < 75 years vs aged ≥ 75 years) and revascularization availability at presenting hospital. Logistic regression was used to determine the adjusted effect of sex on mortality and to determine predictors of revascularization. RESULTS: The incidence of CS was higher in women (3.7% of female vs 2.7% of male AMI patients; P < 0.001). Women with CS were older than men (mean age: 75.5 vs 71.1 years; P < 0.001) and less likely to present to revascularization-capable sites (16% vs 19.2%; P < 0.001). Unadjusted 1-year mortality rates were higher in women (80.3% vs 75.4%; P < 0.001). Women were less likely to be revascularized (12.6% vs 17.6%; P < 0.001) and less likely to be transferred when they presented to nonrevascularization sites (11.3% vs 14.2%; P < 0.001). The strongest predictor of revascularization was presentation to a revascularization-capable site (odds ratio, 17.69; P < 0.001). After regression adjustment, there were no significant differences in mortality or revascularization between the sexes. CONCLUSION: Women with CS are older than men with CS and are less likely to present to revascularization-capable sites. This accounts for the lower unadjusted revascularization rates among women compared with men. However, there are no significant sex-based differences in adjusted mortality rates.

Chordal replacement with polytetrafluoroethylene sutures for mitral valve repair: a 25-year experience.

OBJECTIVE: The study objective was to examine the late results of mitral valve repair with chordal replacement with polytetrafluoroethylene sutures. METHODS: From 1986 to 2004, 606 consecutive patients with degenerative mitral regurgitation had mitral valve repair with chordal replacement with polytetrafluoroethylene sutures. Patients' mean age was 57 years, and 73.6% were men. Isolated prolapse of the anterior leaflet was present in 17.6% of patients, isolated posterior leaflet prolapse was present in 29.5% of patients, and bileaflet prolapse was present in 52.9% of patients. Prolapse was corrected by creating 2 to 38 neochords of polytetrafluoroethylene sutures (mean, 13 ± 9 per patient). The mean follow-up was 10.1 years, and 96% of the patients had multiple echocardiographic studies over the years. RESULTS: There were 5 early and 106 late deaths. Age, diabetes, hypertension, chronic obstructive lung disease, New York Heart Association functional classes III and IV, and ejection fraction less than 40% were independent predictors of mortality. At 18 years, freedom from reoperation on the mitral valve was 90.2% ± 2.4%, freedom from recurrent severe mitral regurgitation was 91.0% ± 2.7%, and freedom from moderate or severe mitral regurgitation was 67.5% ± 4.2%. Cox regression analysis revealed that isolated prolapse of the anterior leaflet was predictive of reoperation, and that older age, hypertension, and left ventricular ejection fraction less than 40% were predictive of recurrent moderate or severe mitral regurgitation. CONCLUSIONS: Chordal replacement with polytetrafluoroethylene sutures expands the indication of repair to patients with prolapse of multiple segments. Valve function remains stable in most patients during the first 2 decades of follow-up.

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.

Long-term outcomes using a two-stent technique for the treatment of coronary bifurcations.

BACKGROUND: The crush and culotte are probably the most common two-stent techniques utilized for percutaneous coronary intervention (PCI) of complex bifurcation lesions. Long-term outcome associated with the utilization of these techniques is unknown. Our objective was to evaluate the long-term outcomes after bifurcation PCI utilizing these 2 techniques with a prospective PCI registry. METHODS: Between 11/1/2003 and 12/31/2007, 360 patients were treated with either crush (n=304) or culotte (n=56). Primary outcome was the occurrence of major adverse cardiac events (MACE) defined as the composite of death, myocardial infarction and target vessel revascularization. The major secondary outcome measure was MACE or occurrence of CCS Class ≥ 2 angina. RESULTS: After a median follow-up of 4.1 years (3.0-5.1), the occurrence of MACE was 23.9%. MACE or CCS Class ≥ 2 angina occurred in 27.5% of patients. Multivariable analysis revealed that creatinine clearance <60 ml/min (odds-ratio [OR]=1.71, 95% CI 1.08-2.71; p=0.022) and left ventricular ejection fraction <40% (OR=2.14, 95% CI 1.21-3.79; p=0.008) were independent predictors of MACE or CCS Class ≥ 2 angina. A larger main vessel reference diameter (OR=0.57, 95% CI 0.61-0.92), bifurcation angle <50% (OR=0.59, 95% CI 0.35-0.92) and a final kissing-balloon inflation (OR=0.75, 95% CI 0.35-0.99) were associated with a lower risk of MACE or CCS Class ≥ 2 angina. CONCLUSIONS: Application of the crush and culotte techniques is associated with efficacy and safety at long-term follow-up. Bifurcation angle, a final kissing balloon inflation and vessel reference diameter are important variables that impact on very long-term outcomes.

Toronto hypertrophic cardiomyopathy genotype score for prediction of a positive genotype in hypertrophic cardiomyopathy.

BACKGROUND: Genotyping in hypertrophic cardiomyopathy has gained increasing attention in the past decade. Its major role is for family screening and rarely influences decision-making processes in any individual patient. It is associated with substantial costs, and cost-effectiveness can only be achieved in the presence of high-detection rates for disease-causing sarcomere protein gene mutations. Therefore, our aim was to develop a score based on clinical and echocardiographic variables that allows prediction of the probability of a positive genotype. METHODS AND RESULTS: Clinical and echocardiographic variables were collected in 471 consecutive patients undergoing genetic testing at a tertiary referral center between July 2005 and November 2010. Logistic regression for a positive genotype was used to construct integer risk weights for each independent predictor variable. These were summed for each patient to create the Toronto hypertrophic cardiomyopathy genotype score. A positive genotype was found in 163 of 471 patients (35%). Independent predictors with associated-risk weights in parentheses were as follows: age at diagnosis 20 to 29 (-1), 30 to 39 (-2), 40 to 49 (-3), 50 to 59 (-4), 60 to 69 (-5), 70 to 79 (-6), ≥80 (-7); female sex (4); arterial hypertension (-4); positive family history for hypertrophic cardiomyopathy (6); morphology category (5); ratio of maximal wall thickness:posterior wall thickness <1.46 (0), 1.47 to 1.70 (1), 1.71 to 1.92 (2), 1.93 to 2.26 (3), ≥2.27 (4). The model had a receiver operator curve of 0.80 and Hosmer-Lemeshow goodness-of-fit P=0.22. CONCLUSIONS: The Toronto genotype score is an accurate tool to predict a positive genotype in a hypertrophic cardiomyopathy cohort at a tertiary referral center.

Relationship of bipolar and unipolar electrogram voltage to scar transmurality and composition derived by magnetic resonance imaging in patients with nonischemic cardiomyopathy undergoing VT ablation.

BACKGROUND: Bipolar voltage mapping has a role in defining endocardial-based scar in postinfarct patients undergoing ventricular tachycardia catheter ablation. The utility of bipolar and unipolar voltages in characterizing scar has not been evaluated in patients with nonischemic cardiomyopathy. OBJECTIVE: To relate left ventricular (LV) endocardial bipolar and unipolar voltages in these patients to scar transmurality (endocardial vs nonendocardial) and composition (homogeneous core vs heterogeneous gray). METHODS: Ten consecutive cardiomyopathy patients undergoing endocardial LV tachycardia ablation were included (age 48 ± 14 years; left ventricular ejection fraction 43% ± 15%). Preablation late gadolinium-enhanced magnetic resonance imaging was used to quantify core and gray scar by using signal-intensity thresholding. Electroanatomic LV endocardial mapping provided bipolar and unipolar voltages. Electroanatomic maps and late gadolinium-enhanced magnetic resonance imaging were rigidly registered in order to relate voltage to scar (registration error 3.6 ± 2.9 mm). RESULTS: Bipolar voltage was lower in endocardial core than in no scar (P <.001). Unipolar voltage was lower in endocardial core and nonendocardial core than in no scar (P <.001). Endocardial and nonendocardial gray scar had an effect similar to that of core in reducing bipolar and unipolar voltages (P <.001). The mass of healthy myocardium and endocardial core scar independently predicted bipolar and unipolar voltages using general estimating equation modeling. With receiver operating characteristic curve analysis, bipolar voltage >1.9 mV and unipolar voltage <6.7 mV had a high negative predictive value (91%) for detecting nonendocardial scar from either endocardial scar or no scar. CONCLUSIONS: In patients with nonischemic cardiomyopathy, LV endocardial bipolar voltage is dependent on endocardial core and gray scar, while the unipolar voltage is influenced by core and gray scar across the LV wall as defined by late gadolinium-enhanced magnetic resonance imaging.

Quantification of mitral valve anatomy by three-dimensional transesophageal echocardiography in mitral valve prolapse predicts surgical anatomy and the complexity of mitral valve repair.

BACKGROUND: Three-dimensional (3D) transesophageal echocardiography (TEE) is more accurate than two-dimensional (2D) TEE in the qualitative assessment of mitral valve (MV) prolapse (MVP). However, the accuracy of 3D TEE in quantifying MV anatomy is less well studied, and its clinical relevance for MV repair is unknown. METHODS: The number of prolapsed segments, leaflet heights, and annular dimensions were assessed using 2D and 3D TEE and compared with surgical measurements in 50 patients (mean age, 61 ± 11 years) who underwent MV repair for mainly advanced MVP. RESULTS: Three-dimensional TEE was more accurate (92%-100%) than 2D TEE (80%-96%) in identifying prolapsed segments. Three-dimensional TEE and intraoperative measurements of leaflet height did not differ significantly, while 2D TEE significantly overestimated the height of the posterior segment P1 and the anterior segment A2. Three-dimensional TEE quantitative MV measurements were related to surgical technique: patients with more complex MVP (one vs two to four vs five or more prolapsed segments) showed progressive enlargement of annular anteroposterior (31 ± 5 vs 34 ± 4 vs 37 ± 6 mm, respectively, P = .02) and commissural diameters (40 ± 6 vs 44 ± 5 vs 50 ± 10 mm, respectively, P = .04) and needed increasingly complex MV repair with larger annuloplasty bands (60 ± 13 vs 67 ± 9 vs 72 ± 10 mm, P = .02) and more neochordae (7 ± 3 vs 12 ± 5 vs 26 ± 6, P < .01). CONCLUSIONS: Measurements of MV anatomy on 3D TEE are accurate compared with surgical measurements. Quantitative MV characteristics, as assessed by 3D TEE, determined the complexity of MV repair.

Latent microvolt T-wave alternans in survivors of unexplained cardiac arrest unmasked by epinephrine challenge.

BACKGROUND: The arrhythmogenic substrate in survivors of unexplained cardiac arrest (UCA) has not been defined. OBJECTIVES: To test the hypothesis that patients with UCA have latent repolarization abnormalities, in particular T-wave alternans (TWA), which may be unmasked with epinephrine (EPI) challenge. METHODS: We prospectively studied 10 UCA survivors (46 ± 9 years) and 11 first-degree relatives (FDRs) of sudden death victims (37 ± 14 years). Patients with UCA underwent standard clinical testing, which was normal. FDRs had normal clinical history and testing. All subjects underwent an EPI infusion (0.05, 0.1, and 0.2 µg/(kg·min), 5 minutes each dose) while recording continuous digital 12-lead electrocardiograms. Corrected QT interval and QT variability index were evaluated at each EPI dose. TWA magnitude (V(alt)) was assessed at each dose by using the spectral method. Positive (+) TWA at each dose was defined as V(alt) > 0 with k ≥ 3 in 1 or more 128-beat segment in ≥2 electrocardiogram leads. A novel metric, TWA burden, reflecting V(alt) integrated over time (s), was also evaluated for each EPI dose. RESULTS: There was no difference between UCA survivors and FDRs with respect to heart rate, QT, corrected QT interval, or QT variability index at baseline or during EPI. At baseline, +TWA was similar between UCA survivors and FDRs (10% vs 0%; P = NS). During EPI, +TWA was more prevalent in UCA survivors than in FDRs (80% vs 18%; P = .009). TWA burden was greater in UCA survivors than in FDRs during EPI 0.1 (P = .039) and EPI 0.2 µg/(kg·min) (P = .009). CONCLUSIONS: UCA survivors are more likely to demonstrate latent TWA compared with FDRs, which becomes manifest with EPI. This novel finding provides evidence for an arrhythmogenic substrate in UCA survivors.

Long-term survival in patients with resting obstructive hypertrophic cardiomyopathy comparison of conservative versus invasive treatment.

OBJECTIVES: The aim of this study was to compare the survival of patients with hypertrophic cardiomyopathy (HCM) and resting left ventricular outflow tract (LVOT) obstruction managed with an invasive versus a conservative strategy. BACKGROUND: In patients with resting obstructive HCM, clinical benefit can be achieved after invasive septal reduction therapy. However, it remains controversial whether invasive treatment improves long-term survival. METHODS: We studied a consecutive cohort of 649 patients with resting obstructive HCM. Total and HCM-related mortality were compared in 246 patients who were conservatively managed with 403 patients who were invasively managed by surgical myectomy, septal ethanol ablation, or dual-chamber pacing. RESULTS: Multivariable analyses (with invasive therapy treated as a time-dependent covariate) showed that an invasive intervention was a significant determinant of overall mortality (hazard ratio: 0.6, 95% confidence interval: 0.4 to 0.97, p = 0.04). Overall survival rates were greater in the invasive (99.2% 1-year, 95.7% 5-year, and 87.8% 10-year survival) than in the conservative (97.3% 1-year, 91.1% 5-year, and 75.8% 10-year survival, p = 0.008) cohort. However, invasive therapy was not found to be a significant independent predictor of HCM-related mortality (hazard ratio: 0.7, 95% confidence interval: 0.4 to 1.3, p = 0.3). The HCM-related survival was 99.5% (1 year), 96.3% (5 years), and 90.2% (10 years) in the invasive cohort, and 97.8% (1 year), 94.6% (5 years), and 86.9% (10 years) in the conservative cohort (p = 0.3). CONCLUSIONS: Patients treated invasively have an overall survival advantage compared with conservatively treated patients, with the latter group more likely to die from noncardiac causes. The HCM-related mortality is similar, regardless of a conservative versus invasive strategy.

Activity with ambulation attenuates diuretic responsiveness in chronic heart failure.

INTRODUCTION: We hypothesized that discharged heart failure (HF) patients could develop clinical congestion despite adhering to prescribed diuretics, because ambulation attenuates diuretic and natriuretic responsiveness. METHODS: We studied 9 patients aged 57 ± 13 (mean ± SD) years with New York Heart Association functional class II-III symptoms and ejection fraction <40% (28 ± 7%) and receiving furosemide (≥80 mg/d [113 ± 53 mg/d]) plus renin-angiotensin system antagonists and beta-blockade. Inulin and p-amminohippuric acid were infused to estimate glomerular filtration rate (GFR) and renal plasma flow (RPF). Furosemide was administered intravenously at 75% of the usual oral morning dose. Participants were randomized to supine (90 minutes recumbancy) or upright (90 minutes sitting and treadmill walking) posture and assumed the other position on their second day. Primary outcome variables were urine volume and sodium excretion 90 minutes after furosemide. RESULTS: On the upright, compared with the supine, day, urine volume (792 ± 484 vs 1,290 ± 503 mL; P = .02) and sodium (79 ± 55 vs 141 ± 61 mmol; P < .01) were attenuated, whereas plasma norepinephrine (4.4 ± 2.7 vs 2.3 ± 1.8 mmol/L; P = .01) and renin (327 ± 250% of supine; P < .01) were augmented. Urinary K+, mean pressure, GFR, and RPF were similar. CONCLUSIONS: Activation of the sympathetic nervous system and renin-angiotensin axis by upright ambulation may attenuate diuresis and natriuresis by increasing proximal tubular reabsorption of sodium and water.

Temporal trends in cardiogenic shock treatment and outcomes among ontario patients with myocardial infarction between 1992 and 2008.

BACKGROUND: Clinical trials have demonstrated that emergent revascularization improves survival of patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). However, rates of uptake and impact on outcomes remain uncertain. METHODS AND RESULTS: We identified 9750 patients (3.1%) with CS among 311 183 AMI patients in the Ontario Myocardial Infarction Database between 1992 and 2008 (55.8% men; mean age, 73 years). CS incidence, mortality, revascularization, and transfers from nonrevascularization sites were studied over 3 periods: period 1, before the 1999 American College of Cardiology/American Heart Association AMI guidelines recommending urgent revascularization for patients <75 years; period 2 (1999 to 2004); and period 3, after 2004 guideline revisions suggesting revascularization for patients ≥75 years. Compared with period 1, period 3 was marked by significantly lower CS incidence (3.4% versus 2.6%), increase in transfers from nonrevascularization sites (10.6% versus 23.9%), and adjusted 1-year mortality rates (81.9% versus 71.5%; all comparisons statistically significant). Admission to nonrevascularization sites was associated with lower revascularization rates (8.6% versus 46.6%, P<0.001) and higher adjusted 1-year mortality rates (78.8% [95% confidence interval, 77.4 to 80.2] versus 71.9% [95% confidence interval, 69.8 to 74.1]). Patients ≥75 years of age were less likely to be revascularized or transferred. The greatest increase in transfers from nonrevascularization sites occurred between periods 1 and 2 for patients <75 years (16.5% to 31.4%; P<0.001) and between periods 2 and 3 for patients ≥75 years (6.7% to 12.8%; P<0.001). CONCLUSIONS: Publication of American College of Cardiology/American Heart Association guidelines was followed by increased revascularization and transfer rates, along with declining mortality rates among Ontario AMI patients with CS. These results highlight possibilities for further improvement, particularly among patients eligible for transfer from nonrevascularization sites.

In-hospital outcomes of very elderly patients (85 years and older) undergoing percutaneous coronary intervention.

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.