Myocardial bridging (MB) is a congenital coronary anomaly characterized by systolic compression of the intramyocardial arterial segment and delayed early diastolic artery relaxation, resulting in reduced vessel luminal diameter in diastole. Current evidence suggests that MB, particularly in the left anterior descending artery, may cause anginal symptoms and/or myocardial ischemia through several different pathophysiological and cellular mechanisms acting independently or synergistically: (1) delayed early diastolic relaxation of intramyocardial arterial segment; (2) impaired endothelial-dependent vasodilation with vessel smooth muscle cell hyperactivity in the coronary artery with MB, especially within the bridged segment; (3) focal (septal) ischemia due to “septal steal” phenomenon; and (4) development and progression of an atherosclerotic lesion in the coronary artery segment proximal to MB. Patients with isolated-MB may also experience anginal pain and/or myocardial ischemia due to concomitant structural and/or functional abnormalities of the coronary microcirculation. Both MB and coronary microvascular dysfunction refer to a subgroup of patients with angina and/or ischemia with non-obstructive coronary arteries (ANOCA/INOCA). Therefore, it may be challenging to determine whether MB is causing anginal pain and/or ischemia, particularly since both phenomena have also been reported without MB’s existence. Therefore, comprehensive coronary physiology testing should be encouraged in patients with this coronary anomaly to identify the underlying cause of anginal pain and/or myocardial ischemia, enabling optimal therapeutic strategies in these patients. This review is focused on different pathophysiological and cellular mechanisms of MB-related angina and/or ischemia and future perspectives in the functional assessment of MB severity, bearing in mind the complexity of coronary physiology in the presence of this anomaly.

Type II myocardial infarction (MI), caused by myocardial oxygen supply-demand imbalance rather than acute plaque rupture, represents a growing clinical challenge with high mortality but limited evidence-based management strategies. It requires a rise and/or fall in cardiac troponins with objective evidence of ischemia and should be distinguished from acute myocardial injury without ischemic features. Current guidelines provide limited, but largely diagnostic and principle-based guidance and do not provide trial-validated pathways for coronary evaluation or revascularization in type II MI with coexisting coronary artery disease. Observational studies suggest potential benefit of revascularization and secondary prevention, yet selection bias and procedural risks complicate decision-making. Emerging strategies, including the use of drug-coated balloon (DCB) angioplasty, may offer a balance between invasive therapy and bleeding risk in this high-risk population. This article highlights the diagnostic complexities, therapeutic dilemmas, and the urgent need for randomized trials to define optimal management pathways. A pragmatic framework is proposed, integrating systemic trigger correction, coronary evaluation, physiology-based testing, and individualized revascularization strategies, with emphasis on underutilized guideline-directed medical therapy. The proposed diagnostic and management framework is pragmatic and expert-opinion-based, reflecting current evidence gaps rather than validated trial data.

INTRODUCTION:Functionally optimizing percutaneous coronary intervention (PCI) with post-PCI fractional flow reserve (FFR) measurement has been associated with improved outcomes in native vessels. However, its role in in-stent restenosis (ISR) PCI is not well understood. METHODS:Consecutive patients undergoing PCI for stable angina or stabilized acute coronary syndrome enrolled in a PCI registry were included. FFR was measured pre- and post-PCI with the goal of further optimization of the PCI result based on post-PCI FFR. Target vessel revascularization (TVR) was evaluated in those with optimized FFR (≥0.86) in the ISR and native vessel lesions. RESULTS:There were 675 lesions in 574 patients who underwent pre- and post-PCI FFR with 101 lesions with ISR. ISR group was more likely to present with acute coronary syndrome and to have hypertension and chronic kidney disease. Both groups had long to diffuse disease. Median pre-PCI stenosis (70 %, IQR 60-80 %) and pre-PCI FFR (0.69 vs 0.70) were similar in native and ISR groups. There was similar and modest correlation between angiographic severity and pre-PCI FFR in native and ISR lesions (-0.57[-0.62 to -0.51] and -0.54 [-0.67 to -0.38], both p < 0.0001). Similar proportions of stenosis were functionally optimized to a post-PCI FFR ≥0.86 (66 % vs 71 %, p = 0.7). Despite functional optimization, TVR was significantly higher in ISR compared to native lesions [HR 0.71, 95 % CI 0.08-0.38 Log rank P < 0.001] even when ISR was treated with a drug-eluting stent. CONCLUSION:Despite functional optimization by post-PCI FFR, TVR is significantly higher after ISR PCI.

Key points Percutaneous balloon pericardiotomy (PBP) involves creation of large hole in the pericardium with balloon inflation to avoid the need for a surgical “window” for treatment of malignant pericardial effusion. The procedure can be safely performed effectively with low complication rate and it can be repeated for recurrent pericardial effusion. The recurrence rate of pericardial effusion was 24.5% with a mean survival of 5.8 months. The subgroup surviving at least 1 month, likely had a longer median survival than the overall group, suggesting its value in a subgroup of patients.

BACKGROUND:The J-CTO investigators recently developed angiographic difficulty scores for each of the three major coronary arteries in patients undergoing first-attempt chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in de novo occlusions. METHODS:We examined the performance of the individual J-CTO scores in a large multicenter registry. RESULTS:The CTO lesion location was as follows: right coronary artery (RCA) 3,805 (54%), left anterior descending artery (LAD) 2,303 (33%), and left circumflex (LCX) 935 (13%). Patients in the PROGRESS-CTO registry were younger, more likely to be female, and had higher J-CTO scores compared with the J-CTO registry. Increasing difficulty scores were associated with lower technical success in the PROGRESS-CTO registry (score 0: 94.4 % - score ≥3: 82.6% for the RCA difficulty score; score 0: 96.4% - score ≥3: 86.1 for the LAD difficulty score; and score 0: 95.4% - score ≥3: 81.2% for the LCX difficulty score). The C-statistic of the coronary artery specific J-CTO scores in the PROGRESS-CTO registry were: LAD 0.69 (95% confidence intervals [CI], 0.64-0.73), LCX 0.63 (95% CI, 0.57-0.69), and RCA 0.61 (95-% CI, 0.58-0.64) with good calibration (Hosmer-Lemeshow p-value >0.05 for all). The AUC of the classic J-CTO score for LAD lesions was similar with the LAD J-CTO score (p-for-difference = 0.26), but worse for LCX (p-for-difference = 0.04) and RCA lesions (p-for-difference = 0.04). CONCLUSION:In the PROGRESS-CTO registry, the coronary artery specific J-CTO scores did not improve prediction of the technical success of CTO-PCI compared with the classic J-CTO score.

Plaque modification microcatheters (PM) (Tornus [Asahi] and Turnpike Gold [Teleflex]) are devices that are mainly used to modify the cap or lesion and maintain good support in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We evaluated the frequency of use and outcomes of plaque modification microcatheters in an international multicenter registry. Plaque modification microcatheters were utilized in 242 cases (1.6%: Tornus in 51% and Turnpike Gold in 49%) with decreasing frequency over time (P-for-trend: 0.007 and 0.035, respectively). Technical and procedural success and the incidence of major cardiac adverse events were similar with Tornus and Turnpike Gold use. PMs are infrequently utilized in CTO-PCI and are associated with high success and acceptable complication rates.

Exercise stress testing (EST) is commonly used to evaluate chest pain, with some labs using 85% of age-predicted maximum heart rate (APMHR) as an endpoint for EST. The APMHR is often calculated using the formula 220-age. However, the accuracy of this formula and 85% APMHR as an endpoint may be questioned. Moreover, failing to reach 85% APMHR (known as chronotropic insufficiency) may also indicate poor cardiovascular prognosis, but measurements, such as percentage heart rate reserve (%HRR), maximum rate pressure product (MRPP), and the maximum metabolic equivalent of tasks (METs) reached during EST may provide better prediction of cardiovascular outcomes than not reaching 85% of APMHR. There is a need to incorporate comprehensive measurements to improve the diagnostic and prognostic capabilities of EST.

Background Coronary pseudoaneurysm is a rare, potentially fatal, complication of coronary intervention. A challenging management case of a giant right coronary pseudoaneurysm is presented.Case summary A 56-year-old man presented with an atypical presentation for ST-elevation myocardial infarction. Initial angiogram showed a crescent-shaped ostial lesion with probable connection to the aorta, which disappeared after placing a drug-eluting stent. A few hours later, patient was found to have staph aureus bacteraemia and infective endocarditis for which he received a prolonged antibiotic course. Patient presented a few weeks later with second degree heart block. Echocardiography showed a large cystic lesion adjacent to the right coronary cusp suspicious for a coronary pseudoaneurysm, which was confirmed with angiography. Attempts to treat it with a covered stent were unsuccessful and patient ultimately underwent surgical resection.Discussion Coronary pseudoaneurysm develops when there is a contained breach of all three layers of the vessel. It may develop from direct iatrogenic trauma to the vessel wall but can be infectious in aetiology. The treatment approach remains uncertain due to limited evidence. Here, we present the diagnostic and technical challenges of managing such an uncommon entity and discuss an algorithm for management.

Intravenous unfractionated heparin (UFH) is the most frequently used anticoagulant for percutaneous coronary intervention (PCI). Intravenous enoxaparin, a low-molecular-weight heparin, has superior pharmacokinetic and pharmacodynamic properties compared with UFH. Multiple trials have shown enoxaparin to be safe and effective in PCI. However, there has not been a contemporary study evaluating its safety and efficacy. To assess its efficacy and safety, intravenous enoxaparin during PCI through radial artery access was evaluated in PCI patients from January 2015 to December 2019. Outcomes included procedural success, all-cause mortality, ischemic complications, and bleeding complications from the time of the procedure until hospital discharge. A total of 1019 consecutive eligible patients were identified. Median age was 63 years, and 70% were men. The indication for PCI was stable and unstable angina in two-thirds of cases (77%). Few patients had myocardial infarction (MI) (2.2%) as the indication for intervention. The procedure was successful in 98.2% of cases. There were no deaths. Procedural MI occurred in 0.3% of patients. Acute stent thrombosis occurred in 0.4%. Urgent revascularization and stroke occurred in 0.1% each. Small wrist hematomas occurred in 0.3% and all were managed conservatively. There was one radial artery pseudoaneurysm. There were no cases of major bleeding. In conclusion, this single-center study showed that intravenous enoxaparin is a reasonable alternative anticoagulant for use in low-risk and elective non-MI PCI through radial artery access.

BACKGROUND AND AIMS:Post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) reflects residual atherosclerotic burden and is associated with future events. How much post-PCI FFR can be predicted based on baseline basic information and the clinical relevance have not been investigated. METHODS:We compiled a multicenter registry of patients undergoing pre- and post-PCI FFR. Machine-learning (ML) algorithms were designed to predict post-PCI FFR levels from baseline demographics, quantitative coronary angiography, and pre-PCI FFR. FFR deviation was defined as actual minus ML-predicted post-PCI FFR levels, and its association with incident target vessel failure (TVF) was evaluated. RESULTS:Median (IQR) pre- and post-PCI FFR values were 0.71 (0.61, 0.77) and 0.88 (0.84, 0.93), respectively. The Spearman correlation coefficient of the actual and predicted post-PCI FFR was 0.54 (95% CI: 0.52, 0.57). FFR deviation was non-linearly associated with incident TVF (HR [95% CI] with Q3 as reference: 1.65 [1.14, 2.39] in Q1, 1.42 [0.98, 2.08] in Q2, 0.81 [0.53, 1.26] in Q4, and 1.04 [0.69, 1.56] in Q5). A model with polynomial function of continuous FFR deviation indicated increasing TVF risk for FFR deviation ≤0 but plateau risk with FFR deviation >0. CONCLUSIONS:An ML-based algorithm using baseline data moderately predicted post-PCI FFR. The deviation of post-PCI FFR from the predicted value was associated with higher vessel-oriented event.

The impact of a previous failure on procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We examined the clinical and angiographic characteristics and procedural outcomes of 9,393 patients who underwent 9,560 CTO PCIs at 42 United States and non-United States centers between 2012 and 2022. A total of 1,904 CTO lesions (20%) had a previous failed PCI attempt. Patients who underwent reattempt CTO PCI were more likely to have a fam-ily history of coronary artery disease (37% vs 31%, p <0.001) and dyslipidemia (87.9% vs 84.3%, p <0.001) but were less likely to have heart failure (25.1% vs 29.5%; p <0.001) and cerebrovascular disease (8.7% vs 10.4%, p = 0.04). Patients with previous failure had a higher Japanese CTO (3.33 +/- 1.16 vs 2.12 +/- 1.19, p <0.001) score and required longer procedure (120 vs 111 minutes, p <0.001) and fluoroscopy (46.9 vs 40.4 minutes, p <0.001) times and higher air kerma radiation dose (2.3 vs 2.1 gray, p = 0.013). Technical success rates (84.3% vs 86.5%, p = 0.011) were lower in patients with a previous failure compared with patients who underwent first-attempt CTO PCI with no significant difference in in-hospital major adverse cardiac events. After adjusting for potential confounders, a previ-ous failure was not associated with technical failure. Operators performing >30 CTO PCIs annually were more likely to achieve technical success in patients with previous fail-ure. In conclusion, a previous failed CTO PCI attempt was associated with higher lesion complexity, longer procedure time, and lower technical success; however, the association with lower technical success did not remain significant in multivariable analysis.(c) 2023 Elsevier Inc. All rights reserved. (Am J Cardiol 2023;193:61-69)

Occupational safety is a fundamental part of training and practice in the cardiac catheminimize radiation exposure for physicians and staff through personal shielding and advances in imaging technology have been etched in societal best practice guidelines1, 2 and are regulated at an institutional and federal level. Musculoskeletal complaints and injury of physicians and CCL personnel are another aspect of occupational safety in the CCL that has received less attention. Such injuries are associated with significant morbidity and attrition.2-4 As cardiovascular procedures become more complex, the physical toll of wearing lead aprons for prolonged periods of time and suboptimal ergonomic conditions is likely to grow and exacerbate musculoskeletal complaints.