Myocardial flow reserve recovery in patients with Takotsubo syndrome: Insights from positron emission tomography.

BACKGROUND: Coronary microvascular dysfunction (CMD) has been implicated in the pathogenesis of Takotsubo syndrome (TTS). Positron emission tomography (PET) plays a key role in the assessment of CMD through myocardial flow reserve (MFR). However, there is limited information on the temporal progression of MFR and its relationship to coronary artery disease (CAD) in TTS patients. METHODS: This study evaluated patients with TTS who underwent cardiac catheterization and PET within one year of hospitalization. Patients were categorized into acute (≤10 days), subacute (11-30 days), and chronic (≥31 days) stages based on post-onset time of PET assessment. MFR values and prevalence of abnormal MFR (<2.0) were compared between stages. Temporal MFR changes in patients with obstructive CAD (≥70% stenosis by coronary angiography), non-obstructive CAD, and normal coronaries were compared. RESULTS: Of the 88 patients studied (mean age 70; 96% female), 52 (59%) were in the acute, 17 (19%) in the subacute, and 19 (22%) in the chronic stage. Median MFR in the acute stage was 2.0 (1.5-2.3), with 58% of patients showing abnormal MFR. A significant time-dependent improvement in MFR was observed (P = 0.002), accompanied by a decreased prevalence of abnormal MFR (P = 0.016). While patients with normal coronaries showed significant MFR improvement over time (P = 0.045), patients with obstructive or non-obstructive CAD demonstrated no improvement across three stages (P = 0.346 and 0.174, respectively). CONCLUSION: PET-derived MFR was impaired in TTS patients during the acute phase, with improvement suggesting potential recovery from CMD over time. The concurrent presence of obstructive CAD might impede this recovery process.

Utility of FFRCT in Patients with Chest Pain.

PURPOSE OF REVIEW: The goal of this article is to review the data supporting the use of fractional flow reserve derived from coronary computed tomography angiography (FFRCT) in patients with chest pain. REVIEW FINDINGS: Numerous clinical trials have demonstrated that the diagnostic accuracy of coronary computed tomography angiography (CCTA) can be improved with the use of FFRCT, primarily due to its superior specificity when compared to CCTA alone. This promising development may help reduce the need for invasive angiography in patients presenting with chest pain. Furthermore, some studies have indicated that incorporating FFRCT into decision-making is safe, with an FFRCT value of ≥ 0.8 being associated with favorable outcomes. While FFRCT has been shown to be feasible in patients with acute chest pain, further large-scale studies are warranted to confirm its utility. The emergence of FFRCT as a tool for the management of patients with chest pain is promising. However, potential limitations require the interpretation of FFRCT in conjunction with clinical context.

A Review of ST-Elevation Myocardial Infarction in Patients with COVID-19.

The Coronavirus disease 2019 (COVID-19) pandemic has led to a significant increase in worldwide morbidity and mortality. Patients with COVID-19 are at risk for developing a variety of cardiovascular conditions including acute coronary syndromes, stress-induced cardiomyopathy, and myocarditis. Patients with COVID-19 who develop ST-elevation myocardial infarction (STEMI) are at a higher risk of morbidity and mortality when compared with their age- and sex-matched STEMI patients without COVID-19. We review current knowledge on the pathophysiology of STEMI in patients with COVID-19, clinical presentation, outcomes, and the effect of the COVID-19 pandemic on overall STEMI care.

Prognostic utility of longitudinal quantification of PET myocardial blood flow early post heart transplantation.

BACKGROUND: Myocardial blood flow (MBF) quantification by Rubidium-82 positron emission tomography (PET) has shown promise for cardiac allograft vasculopathy (CAV) surveillance and risk stratification post heart transplantation. The objective was to determine the prognostic value of serial PET performed early post transplantation. METHODS AND RESULT: Heart transplant (HT) recipients at the University of Ottawa Heart Institute with 2 PET examinations (PET1 = baseline, PET2 = follow-up) within 6 years of transplant were included in the study. Evaluation of PET flow quantification included stress MBF, coronary vascular resistance (CVR), and myocardial flow reserve (MFR). The primary composite outcome was all-cause death, re-transplant, myocardial infarction, revascularization, allograft dysfunction, cardiac allograft vasculopathy (CAV), or heart failure hospitalization. A total of 121 patients were evaluated (79% male, mean age 56 ± 11 years) with consecutive scans performed at mean 1.4 ± 0.7 and 2.6 ± 1.0 years post HT for PET1 and PET2, respectively. Over a mean follow-up of 3.0 (IQR 1.8, 4.6) years, 26 (22%) patients developed the primary outcome: 1 death, 11 new or progressive angiographic CAV, 2 percutaneous coronary interventions, 12 allograft dysfunction. Unadjusted Cox analysis showed a significant reduction in event-free survival in patients with PET1 stress MBF < 2.1 (HR: 2.43, 95% CI 1.11-5.29 P = 0.047) and persistent abnormal PET1 to PET2 CVR > 76 (HR: 2.19, 95% CI 0.87-5.51 P = 0.045). There was no association between MFR and outcomes. CONCLUSION: Low-stress MBF and persistent increased CVR on serial PET imaging early post HT are associated with adverse cardiovascular outcomes. Early post-transplant and longitudinal assessment by PET may identify at-risk patients for increased surveillance post HT.

Dual antiplatelet therapy (PEGASUS) vs. dual pathway (COMPASS): a head-to-head in vitro comparison.

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is prescribed for 1-year after myocardial infarction. Two clinical strategies are considered at 1-year: continuation of DAPT or "Dual Pathway" (DP), using aspirin and rivaroxaban. No head-to-head comparative studies exist. In our in-vitro study, 24 samples of donor blood were treated with clinically proven concentrations of 5 antithrombotic regimens: aspirin, ticagrelor, rivaroxaban, DAPT, and DP. Thrombosis was analyzed using the Total Thrombus Analysis System (T-TAS) to measure both antiplatelet and anticoagulant effects. Flow cytometry was performed to quantify platelet activation. DAPT was the most potent antiplatelet regimen, delaying thrombus onset (p < .0001) and reducing thrombogenicity (p < .0001), relative to control. DP did not delay thrombus formation relative to aspirin alone (p = .69). DP was the most potent anticoagulant regimen, delaying thrombus onset (p < .0001) and reducing thrombogenicity (p < .0001), relative to control. DP showed synergistic antithrombotic effects by delaying thrombus onset (p < .0001) and reducing thrombogenicity (p = .0003), relative to rivaroxaban alone. Flow cytometry showed only DAPT (p = .0023) reduced platelet activation. DP treatment demonstrated synergistic antithrombotic effects over rivaroxaban alone, but no additional antiplatelet synergism over aspirin alone.

Acute kidney injury after radial or femoral artery access in ST-segment elevation myocardial infarction: AKI-SAFARI.

BACKGROUND: Acute kidney injury (AKI) complicating primary percutaneous coronary intervention (PCI) is an independent predictor of short- and long-term outcomes in patients presenting with ST-elevation myocardial infarction (STEMI). Prior studies suggest a lower incidence of AKI in patients undergoing PCI through radial artery compared to femoral artery access; however, no randomized clinical trials have specifically investigated this question in patients presenting with STEMI. METHODS: To determine whether radial access (RA) is associated with a reduced frequency of AKI following primary PCI, we performed a substudy of the SAFARI-STEMI trial. The SAFARI-STEMI trial was an open-label, multicenter trial, which randomized patients presenting with STEMI to RA or femoral access (FA), between July 2011 and December 2018. The primary outcome of this post hoc analysis was the incidence of AKI, defined as an absolute (>0.5 mg/dL) or relative (>25%) increase in serum creatinine from baseline. RESULTS: In total 2,285 (99.3%) of the patients enrolled in SAFARI-STEMI were included in the analysis-1,132 RA and 1,153 FA. AKI occurred in 243 (21.5%) RA patients and 226 (19.6%) FA patients (RR: 0.91, 95% CI: 0.78-1.07, P = .27). An absolute increase in serum creatinine >0.5 mg/dL was seen in 49 (4.3%) radial and 52 (4.5%) femoral patients (RR: 1.04, 95% CI: 0.71-1.53, P = .83). AKI was lower in both groups when the KDIGO definition was applied (RA 11.9% vs FA 10.8%; RR: 0.90, 95% CI: 0.72-1.13, P = .38). CONCLUSIONS: Among STEMI patients enrolled in the SAFARI-STEMI trial, there was no association between catheterization access site and AKI, irrespective of the definition applied. These results challenge the independent association between catheterization access site and AKI noted in prior investigations.

Revisiting the Evidence for Dipyridamole in Reducing Restenosis: A Systematic Review and Meta-analysis.

ABSTRACT: Atherosclerosis remains a leading cause of morbidity and mortality, with revascularization remaining a cornerstone of management. Conventional revascularization modalities remain challenged by target vessel reocclusion-an event driven by mechanical, thrombotic, and proliferative processes. Despite considerable advancements, restenosis remains the focus of ongoing research. Adjunctive agents, including dipyridamole, offer a multitude of effects that may improve vascular homeostasis. We sought to quantify the potential therapeutic impact of dipyridamole on vascular occlusion. We performed a literature search (EMBASE and MEDLINE) examining studies that encompassed 3 areas: (1) one of the designated medical therapies applied in (2) the setting of a vascular intervention with (3) an outcome including vascular occlusion rates and/or quantification of neointimal proliferation/restenosis. The primary outcome was vascular occlusion rates. The secondary outcome was the degree of restenosis by neointimal quantification. Both human and animal studies were included in this translational analysis. There were 6,839 articles screened, from which 73 studies were included, encompassing 16,146 vessels followed up for a mean of 327.3 days (range 7-3650 days). Preclinical studies demonstrate that dipyridamole results in reduced vascular occlusion rates {24.9% vs. 48.8%, risk ratio 0.53 [95% confidence interval (CI) 0.40-0.70], I2 = 39%, P < 0.00001}, owing to diminished neointimal proliferation [standardized mean differences -1.13 (95% CI -1.74 to -0.53), I2 = 91%, P = 0.0002]. Clinical studies similarly demonstrated reduced occlusion rates with dipyridamole therapy [23.5% vs. 31.0%, risk ratio 0.77 (95% CI 0.67-0.88), I2 = 84%, P < 0.0001]. Dipyridamole may improve post-intervention vascular patency and mitigate restenosis. Dedicated studies are warranted to delineate its role as an adjunctive agent after revascularization.

Validation of multiparametric rubidium-82 PET myocardial blood flow quantification for cardiac allograft vasculopathy surveillance.

BACKGROUND: We previously demonstrated high diagnostic accuracy of Rubidium-82 positron emission tomography (PET) myocardial blood flow (MBF) quantification for CAV. The purpose of this study was to validate multiparametric PET detection of CAV by combined rate-pressure-product-corrected myocardial flow reserve (cMFR), stress MBF, and coronary vascular resistance (CVR) assessment. METHODS AND RESULTS: Diagnostic CAV cut-offs of cMFR < 2.9, stress MBF < 2.3, CVR > 55 determined in a previous study (derivation) were assessed in heart transplant recipients referred for coronary angiography and intravascular ultrasound (IVUS) (validation). CAV was defined as International Society of Heart and Lung Transplantation CAV1-3 on angiography; and maximal intimal thickness ≥ 0.5 mm on IVUS. Eighty patients (derivation n = 40, validation n = 40) were included: 80% male, mean age 54±14 years, 4.5±5.6 years post transplant. The prevalence of CAV was 44% on angiography and 78% on IVUS. Combined PET cMFR < 2.9, stress MBF < 2.3, CVR > 55 CAV assessment yielded high 88% (specificity 75%) and 83% (specificity 40%) sensitivity for ≥ 1 abnormal parameter and high 88% (sensitivity 59%) and 90% (sensitivity 43%) specificity for 3 abnormal parameters, in the derivation and validation cohorts, respectively. CONCLUSION: We validate the diagnostic accuracy of multiparametric PET flow quantification by cMFR, stress MBF, and CVR for CAV.

Effect of Moderate vs Mild Therapeutic Hypothermia on Mortality and Neurologic Outcomes in Comatose Survivors of Out-of-Hospital Cardiac Arrest: The CAPITAL CHILL Randomized Clinical Trial.

Importance: Comatose survivors of out-of-hospital cardiac arrest experience high rates of death and severe neurologic injury. Current guidelines recommend targeted temperature management at 32 °C to 36 °C for 24 hours. However, small studies suggest a potential benefit of targeting lower body temperatures. Objective: To determine whether moderate hypothermia (31 °C), compared with mild hypothermia (34 °C), improves clinical outcomes in comatose survivors of out-of-hospital cardiac arrest. Design, Setting, and Participants: Single-center, double-blind, randomized, clinical superiority trial carried out in a tertiary cardiac care center in eastern Ontario, Canada. A total of 389 patients with out-of-hospital cardiac arrest were enrolled between August 4, 2013, and March 20, 2020, with final follow-up on October 15, 2020. Interventions: Patients were randomly assigned to temperature management with a target body temperature of 31 °C (n = 193) or 34 °C (n = 196) for a period of 24 hours. Main Outcomes and Measures: The primary outcome was all-cause mortality or poor neurologic outcome at 180 days. Neurologic outcome was assessed using the Disability Rating Scale, with poor neurologic outcome defined as a score greater than 5 (range, 0-29, with 29 being the worst outcome [vegetative state]). There were 19 secondary outcomes, including mortality at 180 days and length of stay in the intensive care unit. Results: Among 367 patients included in the primary analysis (mean age, 61 years; 69 women [19%]), 366 (99.7%) completed the trial. The primary outcome occurred in 89 of 184 patients (48.4%) in the 31 °C group and in 83 of 183 patients (45.4%) in the 34 °C group (risk difference, 3.0% [95% CI, 7.2%-13.2%]; relative risk, 1.07 [95% CI, 0.86-1.33]; P = .56). Of the 19 secondary outcomes, 18 were not statistically significant. Mortality at 180 days was 43.5% and 41.0% in patients treated with a target temperature of 31 °C and 34 °C, respectively (P = .63). The median length of stay in the intensive care unit was longer in the 31 °C group (10 vs 7 days; P = .004). Among adverse events in the 31 °C group vs the 34 °C group, deep vein thrombosis occurred in 11.4% vs 10.9% and thrombus in the inferior vena cava occurred in 3.8% and 7.7%, respectively. Conclusions and Relevance: In comatose survivors of out-of-hospital cardiac arrest, a target temperature of 31 °C did not significantly reduce the rate of death or poor neurologic outcome at 180 days compared with a target temperature of 34 °C. However, the study may have been underpowered to detect a clinically important difference. Trial Registration: ClinicalTrials.gov Identifier: NCT02011568.

Impact of trainee involvement on patient radiation exposure and contrast volumes during invasive cardiac procedures.

PURPOSE: The impact of cardiology fellows (CFs) and interventional cardiology fellows (ICFs) on patient radiation and contrast exposure during diagnostic coronary angiography and percutaneous coronary intervention is unknown. METHODS: Between 2011 and 2014, 16,175 cases were retrospectively assessed involving 27 CFs, 22 ICFs and 24 staff as primary operators. RESULTS: During diagnostic coronary angiography, ICFs administered the lowest radiation dose (5,648±5,523 cGy*cm2; 1.30 ± 1.27 mSv)-achieving 22% less radiation than the staff (6,889±4,294 cGy*cm2; 1.58 ± 0.99 mSv) and 36% less than CFs (7,700±6,751 cGy*cm2; 1.77 ± 1.55 mSv) (p<0.01). When adjusted for access site, CFs administered more radiation than either the ICFs or staff. However, differences between ICFs and staff were exclusively observed during transradial procedures (p<0.01). With regards to contrast administration, ICFs administered less contrast (126.3 ± 57.6 mL) than either CFs (130±52.4 mL) or staff (132.7±47.6 mL) (p<0.01)-again, a finding isolated to the transradial cohort. Of the 6,751 percutaneous coronary intervention cases, no significant differences existed between the ICFs or staff cardiologists in patient radiation exposure-but a CF as the primary operator resulted in an 18% increase in radiation exposure. Notably, contrast use was not different amongst the types of operators (p<0.05). CONCLUSION: In conclusion, having a cardiology fellow as primary operator during invasive cardiac procedures increases patient radiation exposure and minimally increases contrast administration. Strategies to minimize patient radiation exposure while maintaining trainee involvement should be evaluated.

Impact of preoperative fractional flow reserve on arterial bypass graft anastomotic function: the IMPAG trial.

AIMS: Visual estimation is the most commonly used method to evaluate the degree of coronary artery stenosis prior to coronary artery bypass grafting. In interventional cardiology, the use of fractional flow reserve (FFR) to guide revascularization decisions has become routine. We investigated whether the preoperative FFR measurement of coronary lesions is associated with anastomosis function 6 months after surgical revascularization using a multiarterial grafting strategy. METHODS AND RESULTS: In this prospective double-blind study, 67 patients were enrolled from two institutions in Europe and Canada. From these patients, 199 coronary lesions were assessed visually and with FFR at the time of the preoperative angiogram. All patients received coronary revascularization using multiple arterial grafts. A post-operative 6-month angiogram was performed to assess anastomosis functionality using a described angiographic method. The primary outcome was the association between preoperative FFR values and anastomosis function 6 months after surgery. Preoperative FFR was significantly associated with 6-months anastomotic function for all conduits and for all targets (P < 0.001). An FFR value of ≤0.78 was associated with an anastomotic occlusion rate of 3%. CONCLUSION: We found a significant association between the preoperative FFR measurement of the target vessel and the anastomotic functionality at 6 months, with a cut-off of 0.78. Integration of FFR measurement into the preoperative diagnostic workup before multiarterial coronary surgical revascularization leads to improved anastomotic graft function. CLINICAL TRIALS. GOV IDENTIFIER: NCT02527044.

In-hospital outcomes of STEMI patients on warfarin undergoing primary PCI.

OBJECTIVES: We sought to describe the safety and efficacy outcomes of patients on warfarin presenting with ST-elevation myocardial infarction (STEMI). BACKGROUND: Limited data exist on the outcomes and optimal management of STEMI patients on warfarin undergoing primary percutaneous coronary intervention (PCI). METHODS: Baseline characteristics and outcomes were prospectively collected for 2,390 consecutive STEMI patients referred for primary PCI. Patients were stratified based on warfarin use at baseline. The primary safety endpoint was the rate of in-hospital bleeding (a composite of major bleeding or minor bleeding) according to the thrombolysis in myocardial infarction (TIMI) classification. Efficacy endpoints included major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or stroke, as well as intracranial bleeding, cardiogenic shock, and length of stay. Multiple logistic regression was used to determine if warfarin was independently associated with bleeding and MACE. RESULTS: Warfarin patients (n = 59 vs. n = 2,331) were significantly older (73.2 years vs. 61.7 years; P < 0.01), and more likely to present as Killip Class IV (13.6% vs. 2.7%; P < 0.01). TIMI major/minor bleeding occurred in 30.4% of the warfarin patients and 14.2% of the control patients (P < 0.01). After adjustment warfarin was independently associated with an increased risk of bleeding (OR 2.08; P = 0.04). Warfarin patients also had an increased frequency of MACE (20.3% vs. 5.9%; P < 0.01), though this was not significant after adjustment (OR 2.00; P = 0.10). CONCLUSIONS: STEMI patients on warfarin referred for primary PCI are more likely to experience bleeding. New strategies are needed to optimize the management and minimize bleeding in this high-risk population.

Incidence, predictors, and clinical outcomes of early stent thrombosis in acute myocardial infarction patients treated with primary percutaneous coronary angioplasty (insights from the University of Ottawa Heart Institute STEMI registry).

BACKGROUND: Early stent thrombosis (ST) remains an important complication of primary percutaneous intervention (PCI). To date, our information on angiographic and clinical predictors of early ST in ST-segment elevation myocardial infarction (STEMI) patients treated with primary PCI is limited. METHODS: We tried to evaluate the incidence, predictors, and outcomes of early ST in real-world patients treated with primary PCI. We identified all the patients presenting with STEMI between June 2004 and January 2011 who underwent primary PCI as the primary mode of revascularization. Diagnosis of ST was made as per the standard definition proposed by the Academic Research Consortium. RESULTS: The incidence of early ST was 1% among 2,303 patients treated with primary PCI. Definite and probable early ST occurred in 22 and 2 patients, respectively. Patients with early ST had higher in-hospital (P = 0.03) and 30-day mortality (P = 0.048). The rate of cardiogenic shock (P = 0.0006) and cerebrovascular accident (P = 0.0004) was also greater in the early ST group. Smaller stent diameter and lower use of intracoronary glycoprotein IIb/IIIa inhibitor were associated with higher rate of early ST. There was a trend of higher bivalirudin use in ST group, which did not reach significance (P = 0.07) On IVUS imaging, stent malapposition and uncovered plaque area were noted in 6 out of 11 cases. CONCLUSION: The incidence of early ST in primary PCI cohort is low. However, it is still associated with higher mortality and morbidity. Small stent diameter and disuse of intracoronary glycoprotein IIb/IIIa inhibitor may be associated with early ST.

Photoplethysmography using a smartphone application for assessment of ulnar artery patency: a randomized clinical trial.

BACKGROUND: Radial artery access is commonly performed for coronary angiography and invasive hemodynamic monitoring. Despite limitations in diagnostic accuracy, the modified Allen test (manual occlusion of radial and ulnar arteries followed by release of the latter and assessment of palmar blush) is used routinely to evaluate the collateral circulation to the hand and, therefore, to determine patient eligibility for radial artery access. We sought to evaluate whether a smartphone application may provide a superior alternative to the modified Allen test. METHODS: We compared the modified Allen test with a smartphone heart rate-monitoring application (photoplethysmography readings detected using a smartphone camera lens placed on the patient's index finger) in patients undergoing a planned cardiac catheterization. Test order was randomly assigned in a 1:1 fashion. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries (the diagnostic standard). The primary outcome was diagnostic accuracy of the heart rate-monitoring application. RESULTS: Among 438 patients who were included in the study, we found that the heart rate-monitoring application had a superior diagnostic accuracy compared with the modified Allen test (91.8% v. 81.7%, p = 0.002), attributable to its greater specificity (93.0% v. 82.8%, p = 0.001). We also found that this application had greater diagnostic accuracy for assessment of radial or ulnar artery patency in the ipsilateral and contralateral wrist (94.0% v. 84.0%, p < 0.001). INTERPRETATION: A smartphone application used at the bedside was diagnostically superior to traditional physical examination for confirming ulnar patency before radial artery access. This study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient's bedside. Trial registration: Clinicaltrials.gov, no. NCT02519491.

H2 Receptor Antagonists versus Proton Pump Inhibitors in Patients on Dual Antiplatelet Therapy for Coronary Artery Disease: A Systematic Review.

OBJECTIVES: Mitigating the gastrointestinal (GI) bleeding risks of dual antiplatelet therapy (DAPT) is a common clinical concern. While proton pump inhibitors (PPIs) remain the most effective therapy, their adverse events warrant considering alternatives, including Histamine 2 receptor antagonists (H2RAs). METHODS: We searched for randomized controlled trials in MEDLINE, EMBASE, PubMed, and Cochrane Central Register of Controlled Trials, published from 1980 to 2016. After screening, 10 trials were eligible. We compared PPIs to H2RAs in patients on DAPT in terms of 2 clinical and one laboratory outcomes; GI complications, major adverse cardiovascular events (MACE) and high on-treatment platelet reactivity (HTPR). Clinical and statistical inter-study heterogeneity was low for all 3 outcomes (I2 = 0%, p > 0.05 for all). RESULTS: Fixed effects meta-analysis suggested that PPIs were superior to H2RAs in preventing GI complications (OR 0.28, 95% CI 0.17-0.48) but with higher risk of HTPR (OR 1.28, 95% CI 1.030-1.60) though without a higher incidence of MACE (OR 0.99, 95% CI 0.55-1.77). CONCLUSIONS: PPIs are superior to H2RAs for gastroprotection in patients on DAPT. However, PPIs are associated with HTPR, with no significant difference demonstrated in MACE. Based on currently available data, the use of PPIs may be warranted in selected patients on DAPT deemed at risk for GI complications.

Evaluation of Cobalt and Chromium Levels Following Implantation of Cobalt Chromium Coronary Stents: A Pilot Study.

BACKGROUND: Large increases in myocardial trace elements may adversely affect metabolism and become detrimental to cardiac function. Percutaneous coronary intervention (PCI) allows for the revascularisation of obstructive coronary artery disease using drug-eluting stents. These stents are comprised of a metallic stent backbone covered in an engineered polymer which delivers a drug over a prescribed period to the vessel wall. Given the potential implications of trace metal accumulation within the myocardium, our goal is to determine if metallic coronary stents are able to cause detectable elevations in serum cobalt and/or chromium levels. METHODS: This study was a single centre, observational, pilot study with 20 patients who underwent planned PCI with implantation of a cobalt chromium drug eluting stent. Serum blood samples were drawn at baseline prior to PCI, 4hours post-stent deployment and at the time of routine follow-up after PCI. All blood samples were analysed for cobalt and chromium concentrations. The primary outcome of this study was the difference in serum cobalt and chromium levels at routine clinical follow-up. RESULTS: The mean follow up was 64.1±17.3 days. There was no difference in serum cobalt levels when comparing baseline and routine clinical follow up (3.32±2.14nmol/L vs. 3.14±1.00nmol/L, p=0.99) nor in chromium levels (4.24±2.31nmol/L vs. 2.82±1.22 nmol/L, p=0.11). There was also no difference between baseline and 4hours post-PCI serum concentrations. CONCLUSIONS: Percutaneous coronary intervention with cobalt chromium coronary stents does not appear to cause an elevation in these trace element serum concentrations.

Does stent strut design impact clinical outcomes: comparative safety and efficacy of Endeavor Resolute versus Resolute Integrity zotarolimus-eluting stents.

UNLABELLED: Percutaneous coronary intervention is the most commonly performed method of revascularizing obstructive coronary artery disease. The impact of stent strut design on clinical outcomes remains unclear. The Endeavour Resolute (ER-ZES) and the Resolute Integrity (RI-ZES) zotarolimus-eluting stents utilize identical polymers and anti-proliferative agents, differing only in their respective strut design. This study assessed the comparative safety and efficacy of these two stents in unrestricted contemporary real-world practice. METHODS: A total of 542 patients were identified, corresponding to 340 ER-ZES and 480 RI-ZES. The primary endpoint was major adverse cardiac events (MACE) defined by a composite of death, nonfatal myocardial infarction and stroke. Secondary endpoints included post-procedural length of stay, in-stent restenosis, target lesion revascularization, target vessel revascularization, coronary artery bypass grafting and stent thrombosis. RESULTS: MACE occurred in 3.2% of the ER-ZES cohort and 5.0% of the RI-ZES cohort (p= 0.43). Adjusted analysis utilizing propensity score-adjusted odds ratio for MACE, was 1.37 (95% CI 0.46-4.07, p=0.57). The mortality rate (0.9% ER-ZES vs. 1.9% RI-ZES, p=0.59), non-fatal MI (2.3% ER-ZES vs. 3.1% RI-ZES, p=0.75) and stroke (0.0% ER-ZES vs. 0.3% RI-ZES, p=0.85) were not different. Additionally, there was no difference in any of secondary outcomes. CONCLUSIONS: The clinical performance and safety of both ER-ZES and RI-ZES were not statistically different, despite differences in stent strut design.

Less Invasive and Hybrid Surgical/Interventional Coronary Disease Management: The Future Is Now.

Coronary artery bypass grafting (CABG) has evolved to become the criterion standard in elective revascularisation for coronary artery disease (CAD), particularly in patients with complex or multivessel CAD, left main involvement, diabetes mellitus, or left ventricular dysfunction. Despite the superiority of CABG in patients with the most advanced forms of CAD, a standard CABG operation, through a median sternotomy and with the use of cardiopulmonary bypass, carries well recognised challenges. In this article, we describe newer approaches, such as off-pump CABG, minimally invasive bypass grafting, robotic CABG, and hybrid coronary revascularisation, which we consider as necessary ways to minimise invasion, reduce recovery time, provide the benefits of arterial grafting to more patients, and offer alternatives to mitigate the adverse effects of conventional sternotomy and cardiopulmonary bypass.

Pathophysiology of Myocardial Infarction With Nonobstructive Coronary Artery Disease: A Contemporary Systematic Review.

Background: Myocardial infarction with nonobstructive coronary artery disease (MINOCA) is defined as acute myocardial infarction (AMI) with angiographically nonobstructive coronary artery disease. MINOCA represents 6% of all AMI cases and is associated with increased mortality and morbidity. However, the wide array of pathophysiological factors and causes associated with MINOCA presents a diagnostic conundrum. Therefore, we conducted a contemporary systematic review of the pathophysiology of MINOCA. Methods: A comprehensive systematic review of MINOCA was carried out through the utilization of the PubMed database. All systematic reviews, meta-analyses, randomized controlled trials, and cohort studies available in English or French that reported on the pathophysiology of MINOCA published after January 1, 2013 were retained. Results: Of the 600 identified records, 80 records were retained. Central to the concept of MINOCA is the definition of AMI, characterized by the presence of myocardial damage reflected by elevated cardiac biomarkers in the setting of acute myocardial ischemia. As a result, a structured approach should be adopted to thoroughly assess and address clinically overlooked obstructive coronary artery disease, and cardiac and extracardiac mechanisms of myocyte injury. Once these options have been ruled out, a diagnosis of MINOCA can be established, and the appropriate multimodal assessment can be conducted to determine its specific underlying cause (plaque disruption, epicardial coronary vasospasm, coronary microvascular dysfunction, and coronary embolism and/or spontaneous coronary dissection or supply-demand mismatch). Conclusions: Integrating a suitable definition of AMI and understanding the pathophysiological mechanisms of MINOCA are crucial to ensure an effective multimodal diagnostic evaluation and the provision of adequate tailored therapies.

Contexte: L'infarctus du myocarde sans obstruction des artères coronaires (MINOCA) est défini comme un infarctus aigu du myocarde (IAM) en présence d'une coronaropathie non obstructive confirmée par angiographie. Le MINOCA représente 6 % de tous les cas d'IAM et est associé à une hausse des taux de mortalité et de morbidité. Cependant, le large éventail de facteurs physiopathologiques et de causes associés au MINOCA représente une énigme diagnostique. C'est pourquoi nous avons réalisé une analyse systématique des publications contemporaines sur la physiopathologie du MINOCA. Méthodologie: Une analyse exhaustive des publications sur le MINOCA a été menée au moyen de la base de données PubMed. L'ensemble des analyses systématiques, des méta-analyses, des essais contrôlés randomisés et des études de cohorte publiés en anglais ou en français après le 1er janvier 2013 qui faisaient état de la physiopathologie du MINOCA ont été retenus. Résultats: Parmi les 600 dossiers relevés, 80 ont été retenus. La définition de l'IAM était centrale au concept de MINOCA et était caractérisée par la présence d'une lésion myocardique attestée par des taux élevés de biomarqueurs cardiaques en contexte d'ischémie myocardique aiguë. Par conséquent, une approche structurée devrait être adoptée pour évaluer pleinement et traiter les coronaropathies obstructives qui passent inaperçues en clinique ainsi que les mécanismes cardiaques et extracardiaques des lésions aux myocytes. Une fois ces options exclues, un diagnostic de MINOCA peut être établi et l'évaluation multimodale appropriée peut être menée pour déterminer la cause sous-jacente précise (rupture de plaque, vasospasme d'une artère coronaire épicardique, dysfonction microvasculaire coronarienne et embolie coronarienne et/ou dissection spontanée d'une artère coronaire ou déséquilibre entre apports et besoins). Conclusions: Il est crucial d'intégrer une définition convenable de l'IAM et de comprendre les mécanismes physiopathologiques du MINOCA pour assurer une évaluation diagnostique multimodale efficace et une prestation de traitements adaptés et adéquats.