Simplified Assessment of the Index of Microvascular Resistance.

BACKGROUND: To validate a simplified invasive method for the calculation of the index of microvascular resistance (IMR). METHODS: This is a prospective, single-center study of patients with chronic coronary syndromes presenting with nonobstructive coronary artery disease. IMR was obtained using both intravenous (IV) adenosine and intracoronary (IC) papaverine. Each IMR measurement was obtained in duplicate. The primary objective was the agreement between IMR acquired using adenosine and papaverine. Secondary objectives include reproducibility of IMR and time required for the IMR measurement. RESULTS: One hundred and sixteen IMR measurements were performed in 29 patients. The mean age was 68.8 ± 7.24 years, and 27.6% was diabetics. IMR values were similar between papaverine and adenosine (17.7 ± 7.26 and 20.1 ± 8.6, p=0.25; Passing-Bablok coefficient A 0.58, 95% CI -2.42 to 3.53; coefficient B 0.90, 95% CI -0.74 to 1.07). The reproducibility of IMR was excellent with both adenosine and papaverine (ICC 0.78, 95% CI 0.63 to 0.88 and ICC 0.93, 95% CI 0.87 to 0.97). The time needed for microvascular assessment was significantly shortened by the use of IC papaverine (3.23 (2.84, 3.78) mins vs. 5.48 (4.94, 7.09) mins, p < 0.0001). CONCLUSION: IMR can be reliably measured using IC papaverine with similar results compared to intravenous infusion of adenosine with increased reproducibility and reduced procedural time. This approach simplifies the invasive assessment of the coronary microcirculation in the catheterization laboratory.

Current Indications for Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valves: Valve-in-Valve, Valve-in-Ring, and Valve-in-Mitral Annulus Calcification.

Use of transcatheter mitral valve replacement (TMVR) using transcatheter aortic valves in clinical practice is limited to patients with failing bioprostheses and rings or mitral valve disease associated with severe mitral annulus calcification. Whereas the use of valve-in-valve TMVR appears to be a reasonable alternative to surgery in patients at high surgical risk, much less evidence supports valve-in-ring and valve-in-mitral annulus calcification interventions. Data on the results of TMVR in these settings are derived from small case series or voluntary registries. This review summarizes the current evidence on TMVR using transcatheter aortic valves in clinical practice from the characteristics of the TMVR candidates, screening process, performance of the procedure, and description of current results and future perspectives. TMVR using dedicated devices in native noncalcified mitral valve diseases is beyond the scope of the article.

Adult congenital heart disease in Spain: health care structure and activity, and clinical characteristics.

INTRODUCTION AND OBJECTIVES: To assess the structure of health care delivery and the clinical characteristics of adults with congenital heart disease (ACHD) attending specialized centers in Spain. METHODS: A survey was conducted among 32 Spanish centers in 2014. The centers were classified into 2 levels based on their resources. In 2017, a clinical dataset was collected of all consecutive patients attended for a 2-month period at these centers. RESULTS: A total of 31 centers (97%) completed the survey. Seven centers without specialized ACHD clinics were excluded from the analysis. In 2005, only 5 centers met the requirements for specific care. In 2014, there were 10 level 1 and 14 level 2 centers, with a total of 19 373 patients under follow-up. Health care structure was complete in most centers but only 33% had ACHD nurse specialists on staff and 29% had structured transition programs. Therapeutic procedures accounted for 99% and 91% of those reported by National Registries of Cardiac Surgery and Cardiac Catheterization, respectively. Among attended patients, 48% had moderately complex lesions and 24% had highly complex lesions. Although 46% of patients attending level 2 centers had simple lesions, 17% had complex lesions. CONCLUSIONS: The structure for ACHD health care delivery in Spain complies with international recommendations and is similar to that of other developed countries. Congenital heart diseases under specialized care consist mostly of moderately and highly complex lesions, even in level 2 centers. It would be desirable to reorganize patient follow-up according to international recommendations in clinical practice.

In Vivo Demonstration of Photoacoustic Image Guidance and Robotic Visual Servoing for Cardiac Catheter-Based Interventions.

Cardiac interventional procedures are often performed under fluoroscopic guidance, exposing both the patient and operators to ionizing radiation. To reduce this risk of radiation exposure, we are exploring the use of photoacoustic imaging paired with robotic visual servoing for cardiac catheter visualization and surgical guidance. A cardiac catheterization procedure was performed on two in vivo swine after inserting an optical fiber into the cardiac catheter to produce photoacoustic signals from the tip of the fiber-catheter pair. A combination of photoacoustic imaging and robotic visual servoing was employed to visualize and maintain constant sight of the catheter tip in order to guide the catheter through the femoral or jugular vein, toward the heart. Fluoroscopy provided initial ground truth estimates for 1D validation of the catheter tip positions, and these estimates were refined using a 3D electromagnetic-based cardiac mapping system as the ground truth. The 1D and 3D root mean square errors ranged 0.25-2.28 mm and 1.24-1.54 mm, respectively. The catheter tip was additionally visualized at three locations within the heart: (1) inside the right atrium, (2) in contact with the right ventricular outflow tract, and (3) inside the right ventricle. Lasered regions of cardiac tissue were resected for histopathological analysis, which revealed no laser-related tissue damage, despite the use of 2.98 mJ per pulse at the fiber tip (379.2 mJ/cm2 fluence). In addition, there was a 19 dB difference in photoacoustic signal contrast when visualizing the catheter tip pre- and post-endocardial tissue contact, which is promising for contact confirmation during cardiac interventional procedures (e.g., cardiac radiofrequency ablation). These results are additionally promising for the use of photoacoustic imaging to guide cardiac interventions by providing depth information and enhanced visualization of catheter tip locations within blood vessels and within the beating heart.

[SICI-GISE Position paper: Enhancing radiation safety in the catheterization laboratory]. / Position paper SICI-GISE: Miglioramento della radioprotezione nel laboratorio di Emodinamica.

The radiation dose received by interventional cardiologists during their activity in the catheterization laboratory is a matter of concern in terms of possible deterministic and stochastic risk. At the same time, very often, the knowledge of the effect and consequences of radiation exposure in the interventional cardiology community is limited. This document endorsed by the Italian Society of Interventional Cardiology (SICI-GISE) provides recommendations for cardiologists' radiation protection. Radiation safety considerations dedicated to women and other staff personnel working in the catheterization laboratory are also discussed.

Local DRLs and automated risk estimation in paediatric interventional cardiology.

INTRODUCTION: Cardiac catheterization procedures result in high radiation doses and often multiple procedures are necessary for congenital heart disease patients. However, diagnostic reference levels (DRL) remain scarce. Our first goal was finding the optimal DRL parameter and determining appropriate DRLs. The second goal was to calculate organ doses (OD), effective doses (ED) and lifetime attributable risks (LAR) per procedure and to provide conversion factors based on dose area product (DAP). MATERIALS AND METHODS: DRLs are calculated for each procedure type, as the 75th percentile of the cumulative value per procedure from the corresponding parameter. All irradiation events in the DICOM Structured Reports were automatically processed and simulated using PCXMC, resulting in OD, ED and LAR. Using a Kruskal Wallis H test and subsequent pairwise comparisons, differences in median values of the DRL parameter between procedure types were assessed. RESULTS: Linear regression showed a strong correlation and narrow confidence interval between DAP and product of body weight and fluoroscopy time (BWxFT), even when all procedures (diagnostic and interventional) are combined. Only 15% of the pairwise comparisons were statistically significant for DAP normalized to BWxFT (DAPBWxFT). The latter pairs contained less frequent procedure types with significant outliers. For DAP normalized to BW (DAPBW), 38% of the pairwise comparisons showed statistically significant differences. Conversion factors from DAPBW to OD and ED were reported for various weight groups, due to the higher correlation between DAPBW and both OD and ED than between DAP and both OD and ED. CONCLUSIONS: The P75 of DAPBWxFT for all procedures combined serves as an appropriate DRL value. This facilitates local DRL determination in smaller paediatric centres, which often have insufficient data to produce appropriate DRLs for different procedure types. Conversion factors are more reliable starting from DAPBW instead of DAP and should be used according to the appropriate BW group.

Myocardial Protection in Minimally Invasive Mitral Valve Surgery: Retrograde Cardioplegia Alone Using Endovascular Coronary Sinus Catheter Compared With Combined Antegrade and Retrograde Cardioplegia.

OBJECTIVE: To compare myocardial protection with retrograde cardioplegia alone with antegrade and retrograde cardioplegia in minimally invasive mitral valve surgery (MIMS). DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The authors studied 97 MIMS patients using retrograde cardioplegia alone and 118 MIMS patients using antegrade and retrograde cardioplegia. INTERVENTIONS: The data from patients admitted for MIMS using retrograde cardioplegia (MIMS retro) between 2009 to 2012 were compared with the data from patients undergoing MIMS with antegrade and retrograde cardioplegia (MIMS ante-retro) between 2006 and 2010 (control group). Cardioplegia in the MIMS retro group was delivered solely through an endovascular coronary sinus (CS) catheter positioned under echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia was used in the MIMS ante-retro group. Data regarding myocardial infarction (MI; creatine kinase Mb, troponin T, electrocardiogram), myocardial function, and hemodynamic stability were collected for comparison. MEASUREMENTS AND MAIN RESULTS: Adequate cardioplegia administration (CS pressure >30 mmHg and asystole) was attained in 74.2% of the patients with retrograde cardioplegia alone. In 23.7% of the patients, the addition of an antegrade cardioplegia was necessary. No difference was observed in the incidence of MI (0 MIMS retro v 1 for MIMS ante-retro, p = 0.3623), difficult separation from cardiopulmonary bypass, and postoperative malignant arrhythmia. No difference was found for maximal creatine kinase Mb (39.1 [28.0-49.1] v 37.9 [28.6-50.9]; p = 0.8299) and for maximal troponin T levels (0.39 [0.27-0.70] v 0.47 [0.32-0.79]; p = 0.1231) for MIMS retro and MIMS ante-retro, respectively. However, lactate levels in the MIMS retro group were significantly lower than in the MIMS ante-retro group (2.1 [1.4-3.05] v 2.4 [1.8-3.3], respectively; p = 0.0453). No difference was observed in duration of intensive care unit stay and death. MIMS retro patients had a shorter hospital stay (7.0 [6.0-8.0] v 8.0 [7.0-9.0] days; p = 0.0003). CONCLUSION: Retrograde cardioplegia administration alone provided comparable myocardial protection to antegrade and retrograde cardioplegia during MIMS, but was not sufficient to achieve asystole in one-fifth of patients.

Radiation Safety in the Catheterization Laboratory: Current Perspectives and Practices.

BACKGROUND: There is great variability in radiation safety practices in cardiac catheterization laboratories around the world. METHODS: We performed an international online survey on radiation safety including interventional cardiologists, electrophysiologists, interventional radiologists, and vascular surgeons. RESULTS: A total of 570 responses were received from various geographic locations, including the United States (77.9%), Asia (7.9%), Europe (6.8%), Canada (2.8%), and Mexico and Central America (2.1%). Most respondents (73%) were interventional cardiologists and 23% were electrophysiologists, with 14.4 ± 10.2 years in practice. Most respondents (75%) were not aware of their radiation dose during the past year and 21.2% had never attended a radiation safety course; 58.9% are "somewhat worried" and 31.5% are "very worried" about chronic radiation exposure. Back pain due to lead use was reported by 43.0% and radiation-related health complications including cataracts and malignancies were reported by 6.3%. Only 37.5% of respondents had an established radiation dose threshold for initiating patient follow-up. When comparing United States operators with the other respondents, the former were more likely to attend radiation safety courses (P<.001), wear dosimeters (P<.001), know their annual personal radiation exposure (P<.001), and have an established patient radiation dose threshold (P<.001). They were also more likely to use the fluoro store function, under-table shields, leaded glasses, ceiling lead glass, and disposable radiation shields, and were more concerned about the adverse effects of radiation. CONCLUSIONS: Radiation safety is of concern to catheterization laboratory personnel, yet there is significant variability in radiation protection practices, highlighting several opportunities for standardization and improvement.

Heart Team: Joint Position of the Swiss Society of Cardiology and the Swiss Society of Cardiac Surgery.

The Swiss Society of Cardiology (SSC) and the Swiss Society of Cardiac and ThoracicVascular Surgery (SSCTVS) have formulated their mutual intent of a close, patient-oriented, and expertise-based collaboration in the Heart Team Paper. The interdisciplinary dialogue between the SSC and SSCTVS reflects an attitude in decision making, which guarantees the best possible therapy for the individual patient. At the same time, it is a cornerstone of optimized process quality, placing individual interests into the background. Evaluation of the correct indication for a treatment is indeed very challenging and almost impossible to verify retrospectively. Quality in this very important health policy process can therefore only be assured by the use of mutually recognized indications, agreed upon by all involved physicians and medical specialties, whereby the capacity of those involved in the process is not important but rather their competence. These two medical societies recognize their responsibility and have incorporated international guidelines as well as specified regulations for Switzerland. Former competitors now form an integrative consulting team able to deliver a comprehensive evaluation for patients. Naturally, implementation rests with the individual caregiver. The Heart Team Paperof the SGK and SGHC, has defined guide boards within which the involved specialists maintain sufficient room to maneuver, and patients have certainty of receiving the best possible therapy they require.