Invasive Assessment of Microvascular Resistance in Hypertrophic Cardiomyopathy With Echocardiographic Correlates.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is often associated with ischaemia despite lack of focal epicardial coronary stenosis. Our aim was to assess invasive coronary microvascular circulation and correlate findings with echocardiography. METHODS: We prospectively enrolled patients with HCM and controls who were referred for diagnostic coronary angiography. A pressure-temperature sensor coronary guidewire was used with intracoronary injections of room-temperature saline to measure mean coronary transit time during rest and hyperaemia induced with intravenous adenosine. The index of microvascular resistance (IMR) was calculated. Left ventricular mass was calculated during echocardiographic studies. RESULTS: Patients with HCM (n=12) and controls (n=7), had similar demographics. Left ventricular ejection fraction was higher in HCM (76.7%±11.0% vs 55.0%±15.9%, p=0.003). IMR was non-significantly higher in HCM (21.7±10.2 vs 15.3±4.8, p=0.16). Only patients with HCM had abnormal IMR (>25). Coronary flow reserve was non-significantly higher in HCM (2.7±1.6 vs 2.1±1.2, p=0.34). IMR correlated with left ventricular mass in hypertrophic cardiomyopathy subjects (Pearson r=0.68, p=0.02). CONCLUSIONS: Microvascular dysfunction as assessed by IMR may be abnormal in HCM and is correlated with left ventricular mass.

Radial versus femoral approach for saphenous vein grafts angiography and interventions.

BACKGROUND: Coronary angiography and intervention to saphenous venous grafts (SVGs) remain challenging. This study aimed to investigate the feasibility and safety of the radial approach compared to femoral access in a large cohort of patients undergoing SVG angiography and intervention. METHODS: Data from 1,481 patients from Canada, United States, and Spain who underwent procedures between 2010 and 2016 were collected. Patients must have undergone SVG coronary angiography and/or intervention. Demographics, procedural data, and in-hospital complications were recorded. RESULTS: Procedures were undertaken by either the radial (n = 863, 211 intervention) or femoral (n = 618, 260 intervention) approach. The mean number of SVGs per patient was similar between groups (radial 2.3 ± 0.7 vs femoral 2.6 ± 1.1, P = .61), but the radial group required a fewer number of catheters (2.6 ± 1.7 vs 4.1 ± 1.1, P < .001). Fluoroscopy time was comparable between groups, and there was a trend toward lower contrast volume in the radial group (P = .045). Overall, the total dose of heparin was significantly higher in the radial group (P < .001); however, radial patients experienced significantly less access-site bleeding complications (P < .001). Outpatients undergoing radial SVG interventions had a higher likelihood of a same-day discharge home (P < .001). CONCLUSIONS: Radial access for SVG angiography and intervention is safe and feasible, without increasing fluoroscopy time. In experienced centers, radial access was associated with fewer catheters used, lower contrast volume, and lower rate of vascular access-site bleeding complications. Moreover, outpatients undergoing SVG percutaneous coronary intervention though the radial approach had a higher likelihood of a same-day discharge home.

Is Fractional Flow Reserve Useful in Assessing Coronary Artery Fistula: A Case-Based Discussion and Review.

We present two cases where fractional flow reserve (FFR) was utilised to guide management of coronary artery fistula (CAF), an approach advocated in recent case studies. CAF is a coronary anomaly that may present with a variety of syndromes though is frequently asymptomatic. When to exclude the fistula (surgically or percutaneously) is not always clear. A way to quantify if the fistula is physiologically meaningful would be advantageous. Our findings suggest FFR may only be assessing the concomitant epicardial coronary artery disease (CAD) rather than the degree of coronary steal and its routine use in this setting is not supported.

Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Implantation: Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Silent ischemic embolic lesions are common after transcatheter aortic valve implantation (TAVI). The use of embolic protection devices (EPD) may reduce the occurrence of these embolic lesions. Thus, a quantitative overview and credibility assessment of the literature was necessary to draw a robust message about EPD. Therefore, the aim of this meta-analysis was to study whether the use of EPD reduces silent ischemic and clinically evident cerebrovascular events associated with TAVI. METHODS: We conducted a comprehensive search to identify studies that evaluated patients undergoing TAVI with or without EPD. Random-effects meta-analyses were performed to estimate the effect of EPD compared with no-EPD during TAVI using aggregate data. RESULTS: Sixteen studies involving 1170 patients (865/305 with/without EPD) fulfilled the inclusion criteria. The EPD delivery success rate was reported in all studies and was achieved in 94.5% of patients. Meta-analyses evaluating EPD versus without EPD strategies could not confirm or exclude any differences in terms of clinically evident stroke (relative risk, 0.70; 95% confidence interval [CI], 0.38-1.29; P=0.26) or 30-day mortality (relative risk, 0.58; 95% CI, 0.20-1.64; P=0.30). There were no significant differences in new-single, multiple, or total number of lesions. The use of EPD was associated with a significantly smaller ischemic volume per lesion (standardized mean difference, -0.52; 95% CI, -0.85 to -0.20; P=0.002) and smaller total volume of lesions (standardized mean difference, -0.23; 95% CI, -0.42 to -0.03; P=0.02). Subgroup analysis by type of valve showed an overall trend toward significant reduction in new lesions per patient using EPD (standardized mean difference, -0.41; 95% CI, -0.82 to 0.00; P=0.05), driven by self-expanding devices. CONCLUSIONS: The use of EPD during TAVI may be associated with smaller volume of silent ischemic lesions and smaller total volume of silent ischemic lesions. However, EPD may not reduce the number of new-single, multiple, or total number of lesions. There was only very low quality of evidence showing no significant differences between patients undergoing TAVI with or without EPD with respect to clinically evident stroke and mortality.

Healing of Iatrogenic Coronary Dissection and Intramural Hematoma: Insights From OCT.

A 57-year-old female presented with Canadian Cardiovascular Society class 2 angina and a positive stress test. Angiography was performed via right radial approach, resulting in spiral dissection and TIMI 0 flow.

Transradial-Guided Percutaneous Transaxillary Intra-aortic Balloon Pump Insertion.

Axillary access for an intra-aortic balloon pump allows patients with advanced heart failure (HF) to sit upright and ambulate while waiting for destination therapy or bridging to heart transplantation. We describe the combination of radial access for positioning a 4F pigtail catheter to allow axillary angiography and provide a target for a micropuncture needle entry point in a fully anticoagulated patient with advanced HF.