The COVID-19 Pandemic and Coronary Angiography for ST-Elevation Myocardial Infarction, Use of Mechanical Support, and Mechanical Complications in Canada: A Canadian Association of Interventional Cardiology National Survey.

BACKGROUND: As a result of the COVID-19 pandemic first wave, reductions in ST-elevation myocardial infarction (STEMI) invasive care, ranging from 23% to 76%, have been reported from various countries. Whether this change had any impact on coronary angiography (CA) volume or on mechanical support device use for STEMI and post-STEMI mechanical complications in Canada is unknown. METHODS: We administered a Canada-wide survey to all cardiac catheterization laboratory directors, seeking the volume of CA use for STEMI performed during the period from March 1 2020 to May 31, 2020 (pandemic period), and during 2 control periods (March 1, 2019 to May 31, 2019 and March 1, 2018 to May 31, 2018). The number of left ventricular support devices used, as well as the number of ventricular septal defects and papillary muscle rupture cases diagnosed, was also recorded. We also assessed whether the number of COVID-19 cases recorded in each province was associated with STEMI-related CA volume. RESULTS: A total of 41 of 42 Canadian catheterization laboratories (98%) provided data. There was a modest but statistically significant 16% reduction (incidence rate ratio [IRR] 0.84; 95% confidence interval 0.80-0.87) in CA for STEMI during the first wave of the pandemic, compared to control periods. IRR was not associated with provincial COVID-19 caseload. We observed a 26% reduction (IRR 0.74; 95% confidence interval 0.61-0.89) in the use of intra-aortic balloon pump use for STEMI. Use of an Impella pump and mechanical complications from STEMI were exceedingly rare. CONCLUSIONS: We observed a modest 16% decrease in use of CA for STEMI during the pandemic first wave in Canada, lower than the level reported in other countries. Provincial COVID-19 caseload did not influence this reduction.

INTRODUCTION: Après la première vague de la pandémie de COVID-19, de nombreux pays ont déclaré une réduction de 23 % à 76 % des soins invasifs de l'infarctus du myocarde avec élévation du segment ST (STEMI). On ignore si ce changement a entraîné des répercussions sur le volume d'angiographies coronariennes (AC) ou sur l'utilisation des dispositifs d'assistance mécanique lors de STEMI et des complications mécaniques post-STEMI au Canada. MÉTHODES: Nous avons réalisé un sondage pancanadien auprès de tous les directeurs de laboratoire de cathétérisme cardiaque pour obtenir le volume d'utilisation des AC lors des STEMI réalisées durant la période du 1er mars 2020 au 31 mai 2020 (période de pandémie) et durant 2 périodes témoins (1er mars 2019 au 31 mai 2019 et 1er mars 2018 au 31 mai 2018). Le nombre de dispositifs d'assistance ventriculaire gauche utilisés et le nombre de cas de communications interventriculaires et de ruptures du muscle papillaire diagnostiqués ont également été enregistrés. Nous avons aussi évalué si le nombre de cas de COVID-19 enregistrés dans chaque province était associé au volume d'AC liées aux STEMI. RÉSULTATS: Au total, 41 des 42 laboratoires canadiens de cathétérisme (98 %) ont fourni des données. Lors de la comparaison de la première vague de la pandémie aux périodes témoins, nous avons noté une réduction modeste, mais significative, sur le plan statistique de 16 % (ratio du taux d'incidence [RTI] 0,84; intervalle de confiance à 95 % 0,80-0,87) des AC lors de STEMI. Le RTI n'était pas associé au nombre provincial de cas de COVID-19. Nous avons observé une réduction de 26 % (RTI 0,74; intervalle de confiance à 95 % 0,61-0,89) de l'utilisation de pompes à ballonnet intra-aortique lors de STEMI. L'utilisation d'une pompe Impella et les complications mécaniques après les STEMI étaient extrêmement rares. CONCLUSIONS: Nous avons observé une diminution modeste de 16 % de l'utilisation des AC lors de STEMI durant la première vague de la pandémie au Canada, soit une diminution plus faible que ce que les autres pays ont signalé. Le nombre provincial de cas de COVID-19 n'a pas influencé cette réduction.

Efficacy and Safety of the GuideLiner Mother-in-Child Guide Catheter Extension in Percutaneous Coronary Intervention.

BACKGROUND: Percutaneous coronary intervention (PCI) procedures are increasingly performed on complex tortuous and heavily calcified coronary lesions. The GuideLiner® catheter (Vascular Solutions, Inc. Minneapolis, MN) is a rapid exchange guide catheter extension system. There is paucity of data about the efficacy of this device in complex PCI. Therefore, we aim to report the indications, success, and efficacy of GuideLiner use in treating complex lesion subset in the present study. METHODS: We collected data from all patients in whom the GuideLiner was used to facilitate PCI between April 1, 2011 and December 31, 2014 at a tertiary referral center in Toronto, Canada. Demographic and procedural data were obtained from an institutional prospective data registry. Indications for use of the GuideLiner, and angiographic and procedural data specific to the device were also collected. RESULTS: The GuideLiner was utilized in 307 (317 lesions) of 6105 PCI procedures performed at our institution during the study period. The mean age was 68.4 ± 11.2 years and 82% were male. The majority of lesions were types B2 or C (98%), calcified (86.3%), with proximal tortuosity (88.6%). The overall technical success rate of the GuideLiner was 88%. The procedural success rate was 98.7%. The complication rate was low (1.6%). CONCLUSIONS: Use of the GuideLiner catheter facilitated successful completion of PCI procedures in a majority of patients with complex lesions. Operators should be aware of the potential complications associated with GuideLiner use.

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.

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.

Anterior crackles: a neglected sign?

We report on a man, aged 83 years, with chronic heart failure, atrial fibrillation, right ventricular pacing, and worsening exertional dyspnea who was referred for cardiac resynchronization therapy. Detection by anterior chest auscultation of pulmonary crackles during comfortable supine breathing in the context of documented low filling pressures led to the realization that unrecognized pulmonary fibrosis, not congestion, was the principal cause of his shortness of breath. We propose that the incidental finding in chronic heart failure of diffuse anterior crackles during comfortable supine breathing initiate a workup for alternate disorders such as occult pulmonary fibrosis.

Contemporary management of pregnancy-related coronary artery dissection: A single-centre experience and literature review.

Spontaneous coronary artery dissection (SCAD) is an infrequent event that is most commonly associated with pregnant women or those in the postpartum period. Because of its rarity, the literature describing this condition is confined to sporadic case reports, with few reporting long-term follow-up, and no clear consensus exists on the optimal treatment strategy for these patients. The present article reports a single-centre experience with SCAD, highlighting the issues surrounding its management with a brief description of five cases of pregnancy-associated coronary dissection. The treatment used in these cases ranged from a conservative medical approach to surgical and percutaneous intervention, with one patient proceeding to transplantation. Four of the cases have long-term angiographic follow-up.In addition, a comprehensive review of all previously published cases is presented, and temporal trends in the management strategy are highlighted. Possible pathophysiological mechanisms pertaining to this condition, and the complex diagnostic and therapeutic issues involved, which may affect both patient and fetus, are discussed. Finally, an optimal approach to patients with SCAD, informed by our experience and literature review, is described.

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.

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.

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.

Predictors of long-term outcome after crush stenting of coronary bifurcation lesions: importance of the bifurcation angle.

OBJECTIVES: We hypothesized that the bifurcation angle (BA) may affect the outcome of crush stenting (CS) of bifurcation lesions and thus set out to determine the effect of the BA on outcome of patients undergoing coronary bifurcation CS. METHODS: Of 538 bifurcation PCI cases performed between November 2003 and March 2005, 133 were performed using CS (n = 56), balloon CS (n = 71), or reverse CS (n = 6). Patients were divided into low-angle and high-angle groups using the median BA as the cut point. RESULTS: The median BA was 50 degrees. High-angle patients were more likely to be women (33% vs 15%, P = .02), with a prior percutaneous coronary intervention (26% vs 12%. P = .05) and coronary artery bypass grafting (15% vs 5%, P = .05). Procedural success was 98.5% in the low-angle and 95.4% in the high-angle group (P = nonsignificant). Two high-angle patients had acute stent thrombosis, and 1 died in hospital. Four additional high-angle patients (6.1%) and 1 low-angle patient (1.5%) died (P = nonsignificant) during follow-up. Major adverse cardiac events (MACE) occurred more frequently in the high-angle group (22.7% vs 6.2%, P = .007). Bifurcation angle > or = 50 degrees (P = .004), no final kissing balloon inflation (P = .012), and creatinine clearance < 40 mL/min (P = .031) independently predicted MACE. CONCLUSIONS: Bifurcation angle > or = 50 degrees is an independent predictor of MACE after bifurcation CS, in addition to no final kissing balloon inflation and severe renal dysfunction. A high BA confers a setting of increased turbulent flow that is further exacerbated by suboptimal treatment of the crushed side-branch stent. Further study to improve outcome in this subset of patients is warranted.

How should patients with unstable angina and non-ST-segment elevation myocardial infarction be managed? A meta-analysis of randomized trials.

PURPOSE: Patients with unstable angina or non-ST-segment elevation myocardial infarction (MI) may be managed with either an "invasive" or "conservative" strategy. It is unclear which of these strategies is superior. METHODS: We identified studies with MEDLINE and EMBASE searches (1966-September 2003) and by reviewing reference lists. Studies were included if they were randomized controlled trials comparing management strategies for patients in the early post-unstable angina/non-ST-segment elevation MI period and had follow-up data for at least 3 months. RESULTS: Seven trials that randomized a total of 9212 patients were included. The pooled odds ratio (OR) for all-cause mortality was 0.96 (95% confidence interval [CI]: 0.72 to 1.27). The occurrence of fatal or nonfatal re-infarction was reduced with an invasive strategy (OR 0.73; 95% CI: 0.61 to 0.88) as was readmission to hospital (OR 0.67; 95% CI: 0.48 to 0.94). The endpoints of nonfatal MI and the composite of death or nonfatal MI showed nonsignificant trends favoring an invasive strategy. Trials that included a higher proportion of patients with ST-segment depression on admission and trials in which a larger proportion of patients underwent revascularization showed a greater magnitude of benefit for an invasive strategy. CONCLUSION: For patients with unstable angina/non-ST-segment elevation MI, an invasive strategy reduces rates of fatal or nonfatal re-infarction and hospital readmission, but not all-cause mortality, when compared with a noninvasive strategy. These results suggest that an invasive management strategy should be considered for all patients with unstable angina/non-ST-segment elevation MI and perhaps in particular those with ST-segment depression.

N-acetylcysteine reduces contrast-associated nephropathy but not clinical events during long-term follow-up.

BACKGROUND: Contrast-associated nephropathy (CAN) is associated with increased morbidity and mortality following percutaneous coronary intervention (PCI). N-acetylcysteine (NAC) has been shown to reduce the risk of nephropathy; however, the impact of NAC on long-term clinical outcomes has not been assessed. METHODS: This randomized, double-blind, placebo-controlled trial enrolled 180 patients with moderate renal dysfunction undergoing PCI or coronary angiography with a high likelihood of ad hoc PCI; 171 patients completed the clinical follow-up. Patients received oral NAC (2000 mg/dose, n = 95) or placebo (n = 85) twice a day for 3 doses if randomized the night prior to the procedure, and 2 doses if randomized the day of the procedure. The primary end point was the incidence of a > or =25% increase in serum creatinine level 48 to 72 hours after PCI. Secondary end points were the inhospital incidence of death, nonfatal myocardial infarction, or urgent dialysis, and the 9-month incidence of death, nonfatal myocardial infarction, need for dialysis, or repeat hospitalization for cardiac reasons. RESULTS: CAN occurred in 9.6% of patients assigned to NAC and 22.2% of patients assigned to placebo (P =.04); 1 patient receiving NAC required urgent dialysis. The inhospital composite end point occurred in 7 (7.4%) NAC-treated and 3 (3.5%) placebo-treated patients, P = NS. At 9 months, the composite end point occurred in 23 (24.2%) NAC-treated patients and 18 (21.2%) placebo-treated, P = NS. CONCLUSION: Although high-dose NAC prevented periprocedural CAN, this benefit did not translate into a decrease in adverse outcomes over 9 months. Further studies to determine the clinical utility of this drug are required.

Decorin inhibition of PDGF-stimulated vascular smooth muscle cell function: potential mechanism for inhibition of intimal hyperplasia after balloon angioplasty.

Decorin is a small proteoglycan that binds to transforming growth factor-beta (TGF-beta) and inhibits its activity. However, its interaction with platelet-derived growth factor (PDGF), involved in arterial repair after injury, is not well characterized. The objectives of this study were to assess decorin-PDGF and decorin-PDGF receptor (PDGFR) interactions, the in vitro effects of decorin on PDGF-stimulated smooth muscle cell (SMC) functions and the in vivo effects of decorin overexpression on arterial repair in a rabbit carotid balloon-injury model. Decorin binding to PDGF was demonstrated by solid-phase binding and affinity cross-linking assays. Decorin potently inhibited PDGF-stimulated PDGFR phosphorylation. Pretreatment of rabbit aortic SMC with decorin significantly inhibited PDGF-stimulated cell migration, proliferation, and collagen synthesis. Decorin overexpression by adenoviral-mediated gene transfection in balloon-injured carotid arteries significantly decreased intimal cross-sectional area and collagen content by approximately 50% at 10 weeks compared to beta-galactosidase-transfected or balloon-injured, non-transfected controls. This study shows that decorin binds to PDGF and inhibits its stimulatory activity on SMCs by preventing PDGFR phosphorylation. Decorin overexpression reduces intimal hyperplasia and collagen content after arterial injury. Decorin may be an effective therapy for the prevention of intimal hyperplasia after balloon angioplasty.

Reversible regional wall motion abnormalities on exercise technetium-99m-gated cardiac single photon emission computed tomography predict high-grade angiographic stenoses.

OBJECTIVES: We sought to determine the level of angiographic stenosis at which reversible regional wall motion abnormalities (RWMA) are present on exercise stress technetium-99m (Tc-99m)- gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and whether assessments of stress and rest RWMA add incremental diagnostic information. BACKGROUND: Stress and rest gated SPECT MPI enables the detection of post-exercise stunning. Although some studies have correlated RWMA to the severity of MPI defects, only one previous study correlated RWMA on gated MPI to angiographic findings. However, this correlation excluded patients with rest perfusion defects and did not involve gating of rest images. METHODS: One hundred patients undergoing angiography within six months of exercise stress Tc-99m (sestamibi)-gated SPECT MPI (in the absence of interim cardiac events or revascularization) were recruited. Images were acquired 15 to 30 min after stress and interpreted without knowledge of the Duke treadmill score, left ventricular ejection fraction and angiographic data. RESULTS: The sensitivity of reversible RWMA for angiographic stenoses >70% was 53%, with a specificity of 100%. The presence of reversible RWMA was able to stratify patients with angiographic stenoses of 50% to 79% and 80% to 99% with a high positive predictive value. A good correlation was noted between the presence of reversible RWMA and the coronary artery jeopardy score (R = 0.49, p < 0.0001). Multivariate analysis showed that the post-stress RWMA, Duke treadmill and reversible RWMA scores were significant predictors of angiographic severity. CONCLUSIONS: Post-stress and reversible RWMA, as shown by exercise stress Tc-99m-gated SPECT MPI, are significant predictors of angiographic disease and add incremental value to MPI for the assessment of angiographic severity.