Intentional creation of dissection flaps to treat perforations during chronic total occlusion percutaneous coronary intervention.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries a non-negligible risk of coronary perforation. Definitive treatment of a proximal large vessel perforation often requires the use of covered stents; however, the latter carry significant risk of restenosis and thrombosis, and is not feasible if wire control of the distal vessel has not been achieved. We describe two cases of target vessel perforations during CTO PCI which were treated by the intentional creation of dissection flaps using the subintimal tracking and re-entry technique to seal the perforation.

Extreme coronary radiation doses from intravascular brachytherapy.

PURPOSE: To evaluate coronary artery integrity after very high radiation doses from intravascular brachytherapy (IVBT) in the setting of source asymmetry. METHODS: Ten patients treated for right coronary artery (RCA) in-stent restenosis (ISR) between 2017 and 2021 and for whom follow-up angiograms were available were identified from departmental records. Procedural angiograms, taken to document source position, were used to estimate vascular wall doses. The 2.5 mm proximal source marker was used to estimate the distance from source center to the media and adventitia. Distances were converted to dose (Gy) using the manufacturers' dose fall-off table, measured in water. Follow-up films were scrutinized for any sign of late vascular damage. RESULTS: The average minimal distance from catheter center to the adjacent media and the adventitia was 0.9 mm (±0.2) mm and 1.4 mm (±0.2), respectively. The average maximum media and adventitial doses adjacent to the source were 75 Gy (±26) and 39 Gy (±14), respectively. Follow-up angiograms were available from 0.6 years to 3.9 years following IVBT (median: 1.6 years). No IVBT-treated vascular segment showed signs of degeneration, dissection or aneurysm. CONCLUSION: IVBT vascular wall doses are frequently far higher than prescribed. The lack of complications in this unselected group of patients gives a modicum of reassurance that raising the prescription dose is unlikely to lead to a sudden appearance of complications.

Increased prescription dose for large vessel intravascular brachytherapy.

BACKGROUND: Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy. AIM: To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available. METHODS: Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center. RESULTS: Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm. CONCLUSION: The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

Improved safety and quality in intravascular brachytherapy: A multi-institutional study using failure modes and effects analysis.

PURPOSE: Highlight safety considerations in intravascular brachytherapy (IVBT) programs, provide relevant quality assurance (QA) and safety measures, and establish their effectiveness. METHODS AND MATERIALS: Radiation oncologists, medical physicists, and cardiologists from three institutions performed a failure modes and effects analysis (FMEA) on the radiation delivery portion of IVBT. We identified 40 failure modes and rated the severity, occurrence, and detectability before and after consideration of safety practices. Risk priority numbers (RPN) and relative risk rankings were determined, and a sample QA safety checklist was developed. RESULTS: We developed a process map based on multi-institutional consensus. Highest-RPN failure modes were due to incorrect source train length, incorrect vessel diameter, and missing prior radiation history. Based on these, we proposed QA and safety measures: ten of which were not previously recommended. These measures improved occurrence and detectability: reducing the average RPN from 116 to 58 and median from 84 to 40. Importantly, the average RPN of the top 10% of failure modes reduced from 311 to 172. With QA considered, the highest risk failure modes were from contamination and incorrect source train length. CONCLUSIONS: We identified several high-risk failure modes in IVBT procedures and practical safety and QA measures to address them.

PCI for Flush Occluded Right Coronary Artery: Challenges and Techniques for Success.

A 74-year-old man with prior coronary artery bypass surgery had a failing vein graft to the right coronary artery (RCA). He underwent retrograde chronic total occlusion recanalization of an ostial flush-occluded RCA facilitated by retrograde angioplasty at the aorto-ostial junction after failed retrograde electrocautery. The graft was then sacrificed. (Level of Difficulty: Advanced.).

Image-guided intravascular brachytherapy dose escalation.

PURPOSE: Coronary stents reduce IVBT radiation dose with a single layer by 10-30%. However, the impact of multiple stent layers and stent expansion remains unexplored. Individualized dose adjustments considering variations in stent layers and expansion could improve radiation delivery effectiveness. METHODS: EGSnrc was used to compute the delivered vessel wall dose in various IVBT scenarios. Stent effects were modeled for the stent density of 25%, 50%, and 75% with 1, 2, and 3 layers respectively. Doses were calculated at 1.75 to 5.00 mm away from the source center, normalized to 100% at 2 mm. RESULTS: Dose fall-off increased with increasing stent density. With a single layer, the dose at 2 mm from source fell from 100% of prescription to 92%, 83% and 73% at 25%, 50% and 75% density, respectively. The computed dose to points with increasing radial distance from the source decreased progressively with increasing stent layers. With three layers, at 75% stent density, the dose at 2 mm from source center fell to 38%. CONCLUSIONS: A schema for image-guided IVBT dose adjustment is described. While it would be an improvement over current standard of care, myriad factors remain to be addressed in a comprehensive effort to optimize IVBT.

Failure patterns after intravascular brachytherapy for in-stent coronary restenosis.

INTRODUCTION: One strategy to improve the effectiveness of intravascular brachytherapy (IVBT) is to study its failures. Previous investigations described mostly discrete, focal recurrences, typically at the proximal or distal edges of the irradiated segment after plain angioplasty or bare metal stents. We reviewed failure patterns of 30 unselected drug-eluting stent (DES) patients who had follow-up angiograms for recurrence within their IVBT-treated vessel. METHODS: Records of 53 unselected IVBT patients treated between 2016 and 2021 were reviewed. Thirty of the 53 patients had at least one subsequent percutaneous intervention (PCI) for in-stent restenosis (ISR) after IVBT. Angiographic findings of those 30 patients with ISR within their previously irradiated vessel are reported here. RESULTS: Of the 30 patients, 21 (70%) developed recurrent ISR within the irradiated segment. Six of the 21 patients who failed within the irradiated segment also experienced ISR proximal or distal to the irradiated segment. Only 15 patients (50%) failed exclusively within the irradiated segment. In nine patients (30%), restenosis occurred proximally and/or distally to the irradiated segment, but not inside of the irradiated segment itself. CONCLUSIONS: We have shown here that 50% of failures after coronary IVBT for DES ISR occur exclusively within the irradiated segment. An additional 20% of patients had failure within and outside of the irradiated segment. These percentages suggest that a higher radiation dose might improve the long-term patency rates, a conclusion that should be tempered by the lack of universal follow-up.

Coronary revascularisation outcomes in patients with cancer.

Cancer and coronary artery disease (CAD) overlap in traditional risk factors as well as molecular mechanisms underpinning the development of these two disease states. Patients with cancer are at increased risk of developing CAD, representing a high-risk population that are increasingly undergoing coronary revascularisation. Over 1 in 10 patients with CAD that require revascularisation with either percutaneous coronary intervention or coronary artery bypass grafting have either a history of cancer or active cancer. These patients are typically older, have more comorbidities and have more extensive CAD compared with patients without cancer. Haematological abnormalities with competing risks of thrombosis and bleeding pose further unique challenges during and after revascularisation. Management of patients with concurrent cancer and CAD requiring revascularisation is challenging as these patients carry a higher risk of morbidity and mortality compared with those without cancer, often driven by the underlying cancer and associated comorbidities. However, due to variability by different types and stages of cancer, revascularisation outcomes are specific to cancer characteristics such as the timing of onset, cancer subtype and site, stage, presence of metastases, and cancer-related therapies received. Recent studies have provided insights into defining revascularisation outcomes, procedural considerations and best practices in managing patients with cancer. Nevertheless, many gaps remain that require further studies to inform clinical best practices in this population.

Tip-to-Base LAMPOON for Transcatheter Mitral Valve Replacement With a Protected Mitral Annulus.

OBJECTIVES: The purpose of this study was to evaluate tip-to-base intentional laceration of the anterior mitral leaflet to prevent left ventricular outflow tract obstruction (LAMPOON) in patients undergoing transcatheter mitral valve replacement (TMVR) in annuloplasty rings or surgical mitral valves. BACKGROUND: LAMPOON is an effective adjunct to TMVR that prevents left ventricular outflow tract obstruction (LVOTO). Laceration is typically performed from the base to the tip of the anterior mitral leaflet. A modified laceration technique from leaflet tip to base may be effective in patients with a prosthesis that protects the aortomitral curtain. METHODS: This is a multicenter, 21-patient, consecutive retrospective observational cohort. Patients underwent tip-to-base LAMPOON to prevent LVOTO and leaflet overhang, or therapeutically to lacerate a long anterior mitral leaflet risking or causing LVOTO. Outcomes were compared with findings from patients in the LAMPOON investigational device exemption trial with a prior mitral annuloplasty. RESULTS: Twenty-one patients with a annuloplasty or valve prosthesis-protected mitral annulus underwent tip-to-base LAMPOON (19 preventive, 2 rescue). Leaflet laceration was successful in all and successfully prevented or treated LVOTO in all patients. No patients had significant LVOTO upon discharge. There were 2 cases of unintentional aortic valve injury (1 patient underwent emergency transcatheter aortic valve replacement and 1 patient underwent urgent surgical aortic valve replacement). In both cases, the patients had a supra-annular ring annuloplasty, and the retrograde aortic guiding catheter failed to insulate the guidewire lacerating surface from the aortic root. All patients survived to 30 days. Compared with classic retrograde LAMPOON, there was a trend toward shorter procedure time. CONCLUSIONS: Tip-to-base laceration is a simple, effective, and safe LAMPOON variant applicable to patients with an appropriately positioned mitral annular ring or bioprosthetic valve. Operators should take care to insulate the lacerating surface from adjacent structures.

Appropriate use of multimodality stress testing for chest pain in new patient referrals to cardiologists.

OBJECTIVE: In response to the growing use of imaging-based cardiac stress tests in the evaluation of stable ischemic heart disease, professional societies have developed appropriate use criteria (AUC). AUC will soon be linked to reimbursement of advanced diagnostic imaging for Medicare beneficiaries via Clinical Decision Support Mechanisms (CDSMs). We sought to characterize the frequency and type of stress test utilization for chest pain referrals evaluated by cardiologists and determine appropriateness. METHODS: We conducted a retrospective review of new patient referrals seen by general cardiologists at an academic medical center between 2016 and 2017 for a diagnosis of chest pain or angina. Type of stress test ordered, if any, and its appropriateness (Appropriate, May be appropriate, and Rarely appropriate) were ascertained based on the 2013 multimodality AUC guideline document. RESULTS: There were 535 total outpatients. After applying exclusion criteria, there were 349 patients in the sample; the average age was 52 ± 15 years and 53% were female. Most chest pain was nonanginal (65%). Pretest probability of CAD was most commonly intermediate (54%). A total of 183 patients (52%) were referred for stress testing. The majority of stress tests were considered appropriate (82%) by AUC. CONCLUSION: Most patients referred to cardiologists for evaluation of chest pain or angina had nonanginal chest pain and an intermediate pretest probability of CAD. Stress testing was ordered in about half of these patients and the majority were considered appropriate by AUC. These findings suggest that indiscriminate use of CDSMs may not be warranted.

Contemporary Transcatheter Mitral Valve Replacement for Mitral Annular Calcification or Ring.

OBJECTIVES: The aim of this study was to evaluate outcomes of commercial transcatheter mitral valve replacement (TMVR) for annular rings and calcification using contemporary techniques. BACKGROUND: TMVR is evolving in the absence of other viable treatment options for severe mitral annular calcification and failing ring repairs. The concomitant use of laceration of the anterior mitral valve leaflet to prevent left ventricular outflow tract obstruction and pre-emptive alcohol septal ablation is not well studied in clinical practice. METHODS: A single-center study was conducted of valve-in-mitral annular calcification (ViMAC) and valve-in-ring (ViRing) TMVR from September 2015 to April 2020. In-hospital and 30-day outcomes were assessed. RESULTS: Forty patients underwent TMVR (28 ViMAC and 12 ViRing). Sixteen ViMAC (57%) and 5 ViRing (42%) patients underwent attempted laceration of the anterior mitral valve leaflet to prevent left ventricular outflow tract obstruction. Three patients underwent pre-emptive alcohol septal ablation. The median index hospitalization was 7 days. Six patients died within 30 days of the procedure, 6 (21%) in the ViMAC group and none in the ViRing group. Five patients (13%) had left ventricular outflow tract obstruction: 4 (14%) in the ViMAC cohort and 1 (8%) in the ViRing cohort. Five patients (13%) had either intraprocedural valve embolization or late migration (4 ViMAC and 1 ViRing). Technical success defined according to Mitral Valve Academic Research Consortium criteria was present in 25 patients (63%): 9 (75%) in the ViRing cohort and 16 (57%) in the ViMAC cohort. At 30 days, the mitral valve gradient was significantly reduced (5.5 ± 2.1 vs. 10.6 ± 4.8; p < 0.01). Three patients (8%) had at least moderate residual mitral regurgitation. CONCLUSIONS: Transcatheter ViMAC and ViRing can be successfully performed but frequently require the use of contemporary adjunctive techniques.

Antegrade Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction: A Simplified Technique From Bench to Bedside.

BACKGROUND: Intentional laceration of the anterior mitral leaflet (LAMPOON) is an effective adjunct to transcatheter mitral valve replacement that prevents left ventricular outflow tract (LVOT) obstruction. To date, LAMPOON has been performed in over 150 patients using a retrograde approach that can be technically challenging. A modified antegrade transseptal technique may simplify the procedure. METHODS: Antegrade LAMPOON was developed and tested in nonsurvival pig experiments. Thereafter, antegrade LAMPOON was performed in patients at prohibitive risk of LVOT obstruction. Clinical, procedural, and angiographic details were abstracted from medical records of their index procedure, and were compared with findings in comparable patients at risk of fixed-LVOT obstruction in the LAMPOON investigational device exemption trial. RESULTS: Eight patients at risk of fixed LVOT obstruction underwent antegrade LAMPOON. Leaflet traversal and laceration were technically successful in all. There were no cases of clinically significant LVOT obstruction (mean LVOT gradient at discharge: 5.4±1.4 mm Hg). One patient suffered a ventricular wire perforation, unrelated to the antegrade LAMPOON technique, and did not survive to discharge. At the time of discharge, no patients had an increase of >10 mm Hg in LVOT gradient compared with baseline. Procedure times (from traversal to transcatheter mitral valve replacement) were shorter, compared with the retrograde technique in the LAMPOON investigational device exemption trial (39±09 versus 65±35 minutes). All patients survived (8/8, 100%) the procedure, and 7/8 (88%) survived to 30 days, similar to subjects in the LAMPOON investigational device exemption trial. CONCLUSIONS: Antegrade LAMPOON is an effective, reproducible, and simplified strategy to lacerate the anterior leaflet before transcatheter mitral valve replacement. The authors recommend the technique as the new standard for LAMPOON.

Biomass Fuel Use and Cardiac Function in Nepali Women.

Background: Exposure to household air pollution (HAP) from cooking with biomass fuel affects billions of people. We hypothesized that HAP from woodsmoke, compared to other household fuels, was associated with adverse cardiovascular outcomes, of which there have been few studies. Methods: A cross-sectional study was completed in 299 females aged 40-70 years in Kaski District, Nepal, during 2017-18. All participants underwent a standard 12-lead ECG, ankle and brachial systolic blood pressure measurement, and 2D color and Doppler echocardiography. Current stove type was confirmed by inspection. Blood pressure, height, and weight were measured using a standardized protocol. Hypertension was defined as ≥140/90 mmHg or prior diagnosis. Hemoglobin A1c (HbA1c) was obtained, with diabetes mellitus defined as a prior diagnosis or HbA1C ≥ 6.5%. We used adjusted linear and logistic multivariable regressions to examine the relationship of stove type with cardiac structure and function. Results: The majority of women primarily used liquified petroleum gas (LPG) stoves (65%), while 12% used biogas, and 23% used wood-burning cook-stoves. Prevalence of major cardiovascular risk factors was 35% with hypertension, 19% with diabetes mellitus, and 15% current smokers. After adjustment, compared to LPG, wood stove use was associated with increased indexed left atrial volume (ß = 3.15, 95% CI 1.22 to 5.09) and increased indexed left ventricular end diastolic volume (ß = 7.97, 95% CI 3.11 to 12.83). There was no association between stove type and systemic hypertension, left ventricular mass, systolic dysfunction, diastolic dysfunction, pulmonary hypertension, abnormal ankle-brachial index, or clinically significant ECG abnormalities. Conclusion: Biomass fuel use was associated with increased indexed left atrial volume and increased indexed left ventricular diastolic volume in Nepali women, suggesting subclinical adverse cardiac remodeling from HAP in this cross-sectional study. We did not find evidence of an association with hypertension or typical cardiac sequelae of hypertension. Future studies to confirm these results are needed.

Understanding by General Providers of the Echocardiogram Report.

Echocardiograms are the second most frequently utilized cardiac test after electrocardiograms and are most commonly ordered by noncardiology providers. Echocardiogram reports are designed to communicate a comprehensive interpretation of cardiac function; however, it is not known how well these reports are understood by ordering providers. In order to identify gaps in understanding and target potential areas for improvement, we developed a questionnaire testing various topics reported on a standard transthoracic echocardiogram report. This questionnaire was administered to general medicine and cardiology trainees and attending physicians at 2 large academic institutions. Questionnaire response rate was 81%. There were several topics that were not well understood by general providers; these included viability of an akinetic region, pulmonary artery systolic pressure, left ventricular filling pressure, recognition of abnormal structures, and method of identifying of intracardiac thrombus. In conclusion, strategies such as improved communication techniques and adjustment of reporting format should be implemented to increase the clinical value of the echocardiogram.