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 same-day inter-facility transfer for percutaneous coronary intervention.

BACKGROUND: The use of radial approach for coronary angiography, followed by same-day inter-facility transfer for percutaneous coronary intervention (PCI) has not yet been evaluated. OBJECTIVES: We sought to assess the safety and feasibility of using the transradial as compared to the transfemoral approach in patients undergoing diagnostic angiogram with same-day transfer to a PCI facility. METHODS: Patients that underwent diagnostic coronary angiography between January 2011 and June 2017 in a referring facility, and were transferred for same-day PCI were included. Patients' demographics, as well as procedural data and in-hospital outcome, were collected. RESULTS: Three hundred fifty-two participants were included. Of these, 36 (10.2%) patients received transradial access. Patients in the transradial group were older (68 ± 10 vs 62 ± 12 years, P = 0.007), and received a significantly higher total dose of heparin including both, diagnostic and PCI procedures (5935 ± 1865 vs 10029 ± 2771 units, P < 0.001). None of the transradial patients experienced bleeding or access-related complications. In the transfemoral group, 9 (3%) vascular-access complications were recorded. Contrast volume was lower for transradial patients (177 ± 47 vs 216 ± 75 mL, P < 0.001). A higher proportion of outpatients were discharged from the PCI-center the same day after transradial procedures (53% vs 1.3%, P < 0.001). CONCLUSIONS: Transradial access for inter-facility transfer for PCI after diagnostic angiogram appears safe and feasible, without increasing the risk for ischemic hand complications. Transradial access was associated with fewer bleeding and vascular access-site complications, and with a higher likelihood for a same-day discharge home in outpatients.

Nitroglycerin-Derived Pd/Pa for the Assessment of Intermediate Coronary Lesions.

OBJECTIVES: To assess the predictive value of Pd/Pa after nitroglycerin administration (Pd/Pa[N]) as compared with standard fractional flow reserve (FFR). METHODS: Consecutive patients with intermediate coronary lesions assessed by FFR between January 2014 and October 2015 were included. We measured Pd/Pa at baseline, Pd/Pa(N), and Pd/Pa after incremental doses of intracoronary adenosine. RESULTS: A total of 134 patients (27% females; mean age, 65 years) were included. The diagnostic performance of Pd/Pa(N) and identification of cut-off value for Pd/Pa(N) compared with FFR threshold of 0.8 using receiver-operating characteristic (ROC) area under the curve analysis was between 0.98 (95% confidence interval, 0.95-1.00; P<.05) for 48 µg and 0.86 (95% confidence interval, 0.79-0.94; P<.05) for 240 µg adenosine. Pd/Pa(N) ≤0.8 had 100% positive predictive value. Pd/Pa(N) ≥0.94 provided 100% negative predictive value with a high sensitivity (>92%). Optimal diagnostic accuracy of Pd/Pa(N) was achieved for values ≤0.84. The Pearson's correlation between Pd/Pa(N) and FFR varied between 0.89 for 24 µg adenosine and 0.77 for 240 µg (P<.01). CONCLUSION: Pd/Pa(N) values can be used for diagnosis of hemodynamically significant lesions. Pd/Pa(N) correlates well with standard FFR. Pd/Pa(N) cut-off of ≤0.8 can be considered significant without need for adenosine injection. The value of using adenosine whenever Pd/Pa(N) is ≥0.94 is limited.

Culprit lesion thrombus burden after manual thrombectomy or percutaneous coronary intervention-alone in ST-segment elevation myocardial infarction: the optical coherence tomography sub-study of the TOTAL (ThrOmbecTomy versus PCI ALone) trial.

AIMS: Manual thrombectomy has been proposed as a strategy to reduce thrombus burden during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). However, the effectiveness of manual thrombectomy in reducing thrombus burden is uncertain. In this substudy of the TOTAL (ThrOmbecTomy versus PCI ALone) trial, we compared the thrombus burden at the culprit lesion using optical coherence tomography (OCT) in patients treated with thrombectomy vs. PCI-alone. METHODS AND RESULTS: The TOTAL trial (N = 10 732) was an international, multicentre, randomized trial of thrombectomy (using the Export catheter, Medtronic Cardiovascular, Santa Rosa, CA, USA) in STEMI patients treated with primary PCI. The OCT substudy prospectively enrolled 214 patients from 13 sites in 5 countries. Optical coherence tomography was performed immediately after thrombectomy or PCI-alone and then repeated after stent deployment. Thrombus quantification was performed by an independent core laboratory blinded to treatment assignment. The primary outcome of pre-stent thrombus burden as a percentage of segment analysed was 2.36% (95% CI: 1.73-3.22) in the thrombectomy group and 2.88% (95% CI: 2.12-3.90) in the PCI-alone group (P = 0.373). Absolute pre-stent thrombus volume was not different (2.99 vs. 3.74 mm(3), P = 0.329). Other secondary outcomes of pre-stent quadrants of thrombus, post-stent atherothrombotic burden, and post-stent atherothrombotic volume were not different between groups. CONCLUSION: Manual thrombectomy did not reduce pre-stent thrombus burden at the culprit lesion compared with PCI-alone. Both strategies were associated with low thrombus burden at the lesion site after the initial intervention to restore flow.

Multimodality imaging for assessment of coronary embolus.

Caseous mitral annulus calcification involving aortomitral curtain is a rare occurrence. We report a case of a 64-year-old woman with end-stage renal failure and a candidate for renal transplant who presented with late ST-elevation myocardial infarction. Intracoronary imaging, computed tomography cardiac imaging, and histopathology confirmed coronary embolus into the left main stem artery from an extensive caseous mitral annulus calcification.

Assessment of endothelial function by non-invasive peripheral arterial tonometry predicts late cardiovascular adverse events.

AIMS: There is growing need for the identification of novel non-invasive methodologies for the identification of individuals at risk for adverse cardiovascular (CV) events. We examined whether endothelial dysfunction, as detected by non-invasive peripheral arterial tonometry (EndoPAT), can predict late CV events. METHODS AND RESULTS: Reactive hyperaemia (RH) was induced following upper arm occlusion of systolic blood pressure in 270 outpatients (54 +/- 12 years, 48% female). The natural logarithmic scaled RH index (L_RHI) was calculated from the ratio between the digital pulse volume during RH and at baseline. The patients were followed for CV adverse events (AE: cardiac death, myocardial infarction, revascularization or cardiac hospitalization) during a 7-year follow-up (inter-quartile range = 4.4-8). Cox models were used to estimate the association of EndoPAT results with AE adjusted for age. During the follow-up, AE occurred in 86 patients (31%). Seven-year AE rate was 48% in patients with L_RHI < 0.4 vs. 28% in those with L_RHI >or= 0.4 (P = 0.03). Additional univariate predictors of AE were advancing age (P = 0.02) and prior coronary bypass surgery (P = 0.01). The traditional Framingham risk score was not higher in patients with AE. Multivariate analysis identified L_RHI < 0.4 as an independent predictor of AE (P = 0.03). CONCLUSION: A low RH signal detected by EndoPAT, consistent with endothelial dysfunction, was associated with higher AE rate during follow-up. L_RHI was an independent predictor of AE. Non-invasive assessment of peripheral vascular function may be useful for the identification of patients at risk for cardiac AEs.