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.

Incidence, predictors and longer-term impact of troponin elevation following hybrid chronic total occlusion percutaneous coronary intervention.

OBJECTIVES: We examined the incidence of periprocedural cardiac enzyme rise (PCER) [troponin T (TnT) or high-sensivity (hs)TnT >5× the upper limit of normal (ULN)] and periprocedural myocardial infarction (PMI), predictors of PCER and impact of PCER on the longer-term major adverse cardiac events (MACE) following hybrid chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: PCER and PMI after CTO PCI, risk factors for PCER and its impact on longer-term MACE are not fully understood. METHODS: Among 469 CTO PCI cases performed between 01/2010 and 12/2015, next-day TnT or hsTnT was measured in 455 (97%). We examined the incidence of PCER and PMI (with clinical context or TnT ≥70× ULN). In 269 successful cases who had TnT measured, longer-term MACE (death, MI or target-vessel revascularisation/re-occlusion) were assessed. RESULTS: Overall, 420 CTOs (92.3%) were treated successfully. PCER was documented in 34%, while PMI in 2.9%. By multivariable analyses, higher J-CTO score (OR = 1.3 per point; P = 0.002), lower creatinine clearance (OR = 1.01 per each cc/min decrease; P < 0.0001) and recent MI (OR = 2.4; P = 0.007) were independent pre-PCI risk factors for PCER. Among procedural variables, retrograde approach (OR = 1.9; P = 0.014) and procedure duration (OR = 1.2 per 30 min; P = 0.007) were associated with PCER. At a median follow-up of 396 days following successful CTO PCI, PCER was not associated with higher MACE (9.3% vs. 8.1%; P = 0.60), and was not a predictor of MACE in multivariable analysis. CONCLUSIONS: PCER following hybrid CTO PCI is detected in 1/3 of patients. However, true PMI occurs in 2.9%. PCER does not predict adverse long-term outcomes.

Evaluation of the Microstat™ sublingual PCO2 monitor in ambulatory patients.

Physicians often need to measure arterial PCO2 in clinical practice. Arterial blood gas sampling is typically available only in hospitals and may be unpleasant for patients. Minimally invasive techniques for measuring PCO2 offer the potential for overcoming these limitations. The MicroStat monitor non-invasively measures PCO2 in the sublingual tissues, which should track arterial PCO2 in hemodynamically stable patients. This was a prospective observational study. Patients undergoing routine cardiac catheterization were recruited. Following arterial cannulation, two sequential sublingual PCO2 measurements were taken and a contemporaneous arterial sample was sent for blood gas analysis. For each subject we calculated the mean sublingual-arterial CO2 gradient and the test-retest sublingual PCO2 difference. Twenty-five patients were studied. Mean sublingual-arterial PCO2 gradient was +6.8 mmHg (95 % limits of agreement -3.0 to 16.6 mmHg). Test-retest difference was 3.4 mmHg (95 % limits of agreement -1.1 to 7.9 mmHg), p = 0.11 (Wilcoxon test), repeatability was 11 mmHg. The MicroStat sublingual PCO2 monitor over-estimates arterial PCO2 with wide limits of agreement. Test-retest repeatability was poor. Use of sublingual PCO2 monitoring with the MicroStat monitor cannot currently replace blood gas sampling.

Chronic total occlusion percutaneous coronary intervention case selection and techniques for the antegrade-only operator.

Coronary chronic total occlusions (CTO) remain a difficult lesion subset to treat. Although CTOs are present at coronary angiography in 15-20% of patients, only a small fraction of eligible patients will be offered percutaneous treatment. Recent publications from centers with dedicated CTO programs using the full range of antegrade and retrograde techniques suggest success rates in the range of 90% even when little anatomic exclusion are used. However, many patients with clinically appropriate CTO targets have simpler anatomy that can predictably be managed without the selected skills and equipment. The purpose of this review is to provide skilled percutaneous coronary intervention operators who have not specialized in complex retrograde CTO techniques, an algorithm for the selection and antegrade management of appropriate CTO cases. Core equipment and techniques are discussed.

Renal denervation therapy for resistant hypertension.

OPINION STATEMENT: Hypertension is common and leads to significant cardiovascular morbidity and mortality. Some patients are unable to achieve target blood pressures despite multiple antihypertensive medications; these patients are labeled as having resistant hypertension. To palliate the lack of pharmacologic options, recent technological advances led to the development of an interventional procedure to treat hypertension, namely renal sympathetic denervation. This percutaneous procedure involves the ablation of the afferent and efferent nerves surrounding the renal arteries. Many studies that were primarily observational in nature had very promising results. Systolic blood pressure reductions in the order of 25-30 mm Hg were observed in a series of unblinded studies, leading to the approval and widespread use of this technology across Europe, Australia, and Canada. However, a recent rigorous single blinded sham-controlled clinical trial failed to meet its efficacy endpoints. There are several postulated reasons for the conflicting results, which are discussed in this manuscript. These recent findings make us reflect on the need for rigorous clinical trials prior to the early approval and clinical adoption of novel technologies. At the moment, renal denervation remains an investigational procedure. Several trials are underway using different technologies, which, upon completion, will clarify the proper role of renal denervation for the treatment of patients with resistant hypertension.

Effectiveness of renal denervation therapy for resistant hypertension: a systematic review and meta-analysis.

OBJECTIVES: This study sought to determine the current effectiveness and safety of sympathetic renal denervation (RDN) for resistant hypertension. BACKGROUND: RDN is a novel approach that has been evaluated in multiple small studies. METHODS: We performed a systematic review and meta-analysis of published studies evaluating the effect of RDN in patients with resistant hypertension. Studies were stratified according to controlled versus uncontrolled design and analyzed using random-effects meta-analysis models. RESULTS: We identified 2 randomized controlled trials, 1 observational study with a control group, and 9 observational studies without a control group. In controlled studies, there was a reduction in mean systolic and diastolic blood pressure (BP) at 6 months of -28.9 mm Hg (95% confidence interval [CI]: -37.2 to -20.6 mm Hg) and -11.0 mm Hg (95% CI: -16.4 to -5.7 mm Hg), respectively, compared with medically treated patients (for both, p < 0.0001). In uncontrolled studies, there was a reduction in mean systolic and diastolic BP at 6 months of -25.0 mm Hg (95% CI: -29.9 to -20.1 mm Hg) and -10.0 mm Hg (95% CI: -12.5 to -7.5 mm Hg), respectively, compared with pre-RDN values (for both, p < 0.00001). There was no difference in the effect of RDN according to the 5 catheters employed. Reported procedural complications included 1 renal artery dissection and 4 femoral pseudoaneurysms. CONCLUSIONS: RDN resulted in a substantial reduction in mean BP at 6 months in patients with resistant hypertension. The decrease in BP was similar irrespective of study design and type of catheter employed. Large randomized controlled trials with long-term follow-up are needed to confirm the sustained efficacy and safety of RDN.

High prevalence of occult left heart disease in scleroderma-pulmonary hypertension.

Our study aimed to determine the prevalence of occult left-heart disease in patients with scleroderma and pulmonary hypertension. In patients with pulmonary hypertension (mean pulmonary artery pressure (mean PAP)≥25 mmHg), differentiation between pre- and post-capillary pulmonary hypertension has been made according to pulmonary artery wedge pressure (PAWP) less than or more than 15 mmHg, respectively. We performed a retrospective chart review of 107 scleroderma patients. All patients with suspected pulmonary hypertension had routine right or left heart catheterisation with left ventricular end-diastolic pressure (LVEDP) measurement pre-/post-fluid challenge. We extracted demographic, haemodynamic and echocardiographic data. Patients were classified into one of four groups: haemodynamically normal (mean PAP<25 mmHg); pulmonary venous hypertension (PVH) (mean PAP≥25 mmHg, PAWP>15 mmHg); occult PVH (mean PAP≥25 mmHg, PAWP≤15 mmHg, LVEDP>15 mmHg before or after fluid challenge); and pulmonary arterial hypertension (PAH) (mean PAP≥25 mmHg, PAWP≤15 mmHg and LVEDP≤15 mmHg before or after fluid challenge). 53 out of 107 patients had pulmonary hypertension. Based on the PAWP-based definition, 29 out of 53 had PAH and 24 out of 53 had PVH. After considering the resting and post-fluid-challenge LVEDP, 11 PAH patients were reclassified as occult PVH. The occult PVH group was haemodynamically, echocardiographically and demographically closer to the PVH group than the PAH group. PVH had high prevalence in our scleroderma-pulmonary hypertension population. Distinguishing PAH from PVH with only PAWP may result in some PVH patients being misclassified as having PAH.

Hemodynamic stability after transitioning between endothelin receptor antagonists in patients with pulmonary arterial hypertension.

BACKGROUND: Maintenance of a favourable hemodynamic profile is central to therapeutic success in pulmonary arterial hypertension (PAH). There is little information about the safety of transitioning patients between oral therapies for PAH. Endothelin receptor antagonists (ERAs) have been a therapeutic mainstay in PAH, providing benefit to many patients. Three ERAs, bosentan, sitaxsentan, and ambrisentan have been approved for clinical use. Sitaxsentan was voluntarily withdrawn from the market in late 2010 resulting in the need to quickly transition a large number of stable patients. METHODS: We transitioned 30 clinically stable patients to either ambrisentan or bosentan. Patients underwent a right heart catheterization, measurement of serum N-terminal pro-brain natriuretic peptide (NT-proBNP), and assessment of functional class before changing ERA and again 4 months later. We present a retrospective analysis of those data. RESULTS: Of the 30 patients transitioned (15 to ambrisentan, 15 to bosentan), 23 had complete hemodynamic data. No significant change was observed in the groups in right atrial, mean pulmonary artery, and pulmonary artery wedge pressures, or in cardiac output, pulmonary vascular resistance, or NT-proBNP levels. There was no change in World Health Organization functional class. Four ambrisentan and 2 bosentan-treated patients reported fluid retention, and 3 bosentan-treated patients had elevation of hepatic transaminases. Two of the patients had a right atrial pressure increase of ≥5 mm Hg, and 4 had pulmonary artery wedge pressure increase of ≥5 mm Hg. CONCLUSIONS: Transitioning between ERAs in stable PAH patients does not result in hemodynamic or clinical deterioration during the first 4 months posttransition. A minority of patients have developed increased cardiac filling pressures.

Comparison of transradial and femoral approaches for percutaneous coronary interventions: a systematic review and hierarchical Bayesian meta-analysis.

BACKGROUND: Despite lower risks of access site-related complications with transradial approach (TRA), its clinical benefit for percutaneous coronary intervention (PCI) is uncertain. We conducted a systematic review and meta-analysis of clinical studies comparing TRA and transfemoral approach (TFA) for PCI. METHODS: Randomized trials and observational studies (1993-2011) comparing TRA with TFA for PCI with reports of ischemic and bleeding outcomes were included. Crude and adjusted (for age and sex) odds ratios (OR) were estimated by a hierarchical Bayesian random-effects model with prespecified stratification for observational and randomized designs. The primary outcomes were rates of death, combined incidence of death or myocardial infarction, bleeding, and transfusions, early (≤ 30 days) and late after PCI. RESULTS: We collected data from 76 studies (15 randomized, 61 observational) involving a total of 761,919 patients. Compared with TFA, TRA was associated with a 78% reduction in bleeding (OR 0.22, 95% credible interval [CrI] 0.16-0.29) and 80% in transfusions (OR 0.20, 95% CrI 0.11-0.32). These findings were consistent in both randomized and observational studies. Early after PCI, there was a 44% reduction of mortality with TRA (OR 0.56, 95% CrI 0.45-0.67), although the effect was mainly due to observational studies (OR 0.52, 95% CrI 0.40-0.63, adjusted OR 0.49 [95% CrI 0.37-0.60]), with an OR of 0.80 (95% CrI 0.49-1.23) in randomized trials. CONCLUSION: Our results combining observational and randomized studies show that PCI performed by TRA is associated with substantially less risks of bleeding and transfusions compared with TFA. Benefit on the incidence of death or combined death or myocardial infarction is found in observational studies but remains inconclusive in randomized trials.

The retrograde technique for recanalization of chronic total occlusions: a step-by-step approach.

Chronic total occlusion recanalization still represents the final frontier in percutaneous coronary intervention. Retrograde chronic total occlusion recanalization has recently become an essential complement to the classical antegrade approach. In experienced hands, the retrograde technique currently has a high success rate with a low complication profile, despite frequent utilization in the most anatomically and clinically complex patients. Since its initial description, important changes have occurred that make the technique faster and more successful. We propose a step-by-step approach of the technique as practiced at experienced centers in North America. Because the technique can vary substantially, we describe the different alternatives to each step and offer what we perceived to be the most efficient techniques.

Meta-analysis of ten trials on the effectiveness of the radial versus the femoral approach in primary percutaneous coronary intervention.

The radial approach in primary percutaneous coronary intervention (PCI) has been recently assessed in both randomized and observational studies. However, observational studies have several biases that favor the radial approach. We conducted a meta-analysis of randomized controlled trials to compare the clinical outcomes of radial and femoral approach in primary PCI for ST-segment elevation myocardial infarction. The outcomes of interest included death, major bleeding, vascular complications/hematoma, and procedure time. The data were pooled using random-effects models. Ten randomized controlled trials involving 3,347 patients met our inclusion criteria. The radial approach was associated with improved survival (odds ratio 0.53, 95% confidence interval 0.33-0.84) and reduced vascular complications/hematoma (odds ratio 0.35, 95% confidence interval 0.24-0.53). A nonsignificant trend was found toward reduced major bleeding with the radial approach (odds ratio 0.63, 95% confidence interval 0.35-1.12). The procedural time with the radial approach was longer by < 2 minutes (mean difference 1.76 minutes, 95% confidence interval 0.59-2.92). In conclusion, in patients undergoing primary PCI, the radial approach is associated with lower short-term mortality. When feasible, the radial approach should be the favored route in primary PCI.

Prevalence and impact of coronary artery disease in patients with pulmonary arterial hypertension.

The occurrence and impact of coronary artery disease (CAD) among patients with pulmonary arterial hypertension (PAH) are unknown. We aimed to determine the prevalence, clinical correlates, and effect of CAD in patients with PAH. We reviewed the medical records of consecutive patients diagnosed with PAH at a university-based referral center for pulmonary vascular disease from January 1990 to May 2010. The patients systematically underwent right heart catheterization and coronary angiography as a part of their evaluation. The patients with PAH with CAD (defined as ≥50% stenosis in ≥1 major epicardial coronary artery) were compared to patients without CAD. Among the 162 patients with PAH, the prevalence of CAD was 28.4%. The presence of CAD was associated with older age (66.6 ± 11.5 vs 49.2 ± 14.0 years, p <0.001), systemic hypertension, and dyslipidemia. The patients with PAH and CAD had a lower mean pulmonary arterial pressure (44.6 ± 11.1 vs 49.2 ± 14.0 mm Hg; p = 0.02) than patients without CAD. During a median follow-up of 36 months, 73 patients died. The presence of CAD was a predictor of all-cause mortality on univariate analysis (hazard ratio 1.97, 95% confidence interval 1.21 to 3.20) but not on multivariate analysis, which identified older age (hazard ratio 1.03, 95% confidence interval 1.01 to 1.05) and right atrial pressure (hazard ratio 1.08, 95% confidence interval 1.03 to 1.14) as the only independent predictors. In conclusion, our study has demonstrated that CAD is common among patients with PAH. CAD prevalence increases with age, dyslipidemia, and hypertension, but we did not detect an independent prognostic effect of CAD on mortality.

Retrograde recanalization of chronic total occlusions from the transradial approach; early Canadian experience.

BACKGROUND: Retrograde approach for chronic total occlusions (CTO) improves recanalization success rates. Eight French (Fr) catheters and the femoral approach are advocated. OBJECTIVES: Evaluate whether transradial operators can achieve similar success rates using smaller catheters. METHODS: This is a single-operator series of 42 consecutive cases performed between January and December 2010, including 13 while demonstrating CTO recanalization. Patients were referred because of complexity of the CTO or after failed attempt. RESULTS: Most frequent indications for recanalization were CCS 3-4 angina (52%) and CCS 1-2 in 21%. Eighteen (43%) patients underwent previous failed attempts. CTO was in the right coronary in 74%, left anterior descending in 24%, and a left main in 1. Most lesions (88%) were ≥20 mm long and 52% were calcified. We used septal collateral channels (CC) in 33 (79%), epicardial CC in 8 (20%), and a saphenous vein graft in one case. Radial access was used in all patients and was bilateral in 37 (88%). Five cases required one radial and one femoral access. Six French guides were used in 91% for the retrograde side and 71% for the antegrade side. Otherwise, 7 Fr guides were used. The Corsair(®) was used in 38 (90%). Procedural success was achieved in 37 (88%), mostly using reverse controlled antegrade-retrograde tracking (60%) or retrograde crossing (29%). The average <24-h Hb drop was 0.75 ± 0.84 g/dl. No in-hospital major cardiac events occurred. CONCLUSION: Transradial retrograde CTO recanalization is feasible, safe, and still associated with high success rates despite the use of smaller guide catheters.

Effectiveness of recanalization of chronic total occlusions: a systematic review and meta-analysis.

BACKGROUND: Chronic total occlusion (CTO) recanalizations remain extremely challenging procedures. With improvements in technology and techniques, success rates for recanalization of CTO continue to improve. However, the clinical benefits of this practice remain unclear. The aim of the study was to determine the effectiveness of CTO recanalization on clinical outcomes. METHODS: We performed a systematic review and meta-analysis of published studies comparing CTO recanalization to medical management. Data were extracted in duplicate and analyzed by a random effects model. RESULTS: We did not identify any randomized controlled trials or observational studies comparing CTO recanalization to a planned medical management. We did identify 13 observational studies comparing outcomes after successful vs failed CTO recanalization attempt. These studies encompassed 7,288 patients observed over a weighted average follow-up of 6 years. There were 721 (14.3%) deaths of 5,056 patients after successful CTO recanalization compared to 390 deaths (17.5%) of 2,232 patients after failed CTO recanalization (odds ratio [OR] 0.56, 95% CI 0.43-0.72). Successful recanalization was associated with a significant reduction in subsequent coronary artery bypass graft surgery (CABG) (OR 0.22, 95% CI 0.17-0.27) but not in myocardial infarction (OR 0.74, 95% CI 0.44-1.25) or major adverse cardiac events (OR 0.81, 95% CI 0.55-1.21). In the 6 studies that reported angina status, successful recanalization was associated with a significant reduction in residual/recurrent angina (OR 0.45, 95% CI 0.30-0.67). CONCLUSIONS: In highly selected patients considered for CTO recanalization, successful attempts appear to be associated with an improvement in mortality and with a reduction for the need for CABG as compared to failed recanalization. However, given the observational nature of the reviewed evidence, randomized clinical trials are needed to confirm these findings.

Effectiveness and safety of drug-eluting stents in vein grafts: a meta-analysis.

BACKGROUND: The use of drug-eluting stents (DES) in degenerative vein grafts is currently an off-label indication. Recent studies have had conflicting results regarding the effectiveness and safety of this practice. The objective of this meta-analysis was to compare DES to bare-metal stents for the treatment of vein graft stenosis. METHODS: PubMed and the Cochrane clinical trials database were systematically searched to identify all randomized controlled trials (RCTs) and observational studies examining DES for vein graft stenosis published in English between 2003 and 2009. Inclusion criteria included follow-up duration > or =6 months. Data were stratified by study design and pooled using random effects models. RESULTS: Twenty studies were found to meet our inclusion criteria. Eighteen studies were observational and 2 were RCTs. In observational studies, DES were associated with a reduction in major adverse cardiac events (MACE) (odds ratio [OR] 0.50, 95% CI 0.35-0.72), death (OR 0.69, 95% CI 0.53-0.91), target vessel revascularization (TVR) (OR 0.54, 95% CI 0.37-0.79), and target lesion revascularization (TLR) (OR 0.54, 95% CI 0.37-0.78). The incidence of myocardial infarction was similar between groups. In the RCTs, pooled results were inconclusive because of small sample sizes. CONCLUSIONS: Although data from observational studies suggest that the use of DES for vein graft stenosis has favorable effects on MACE, death, TVR, and TLR, these data should be interpreted with caution due to their observational nature. Corresponding RCT data are inconclusive. There remains a need for large multicenter RCTs to address the effectiveness and safety of DES for vein graft stenosis.