Adenosine-Induced Atrial Fibrillation During Coronary Angiography and Fractional Flow Reserve Procedures.

A woman in her sixties presented with a history of progressive shortness of breath, palpitations, and feeling of chest heaviness for the last eight months. To rule out underlying obstructive coronary artery disease, an invasive cardiac catheterization was planned. To assess the hemodynamic significance of the lesion, resting full cycle ratio (RFR) and fractional flow reserve (FFR) values were measured. During this procedure, almost immediately after starting IV adenosine infusion, the patient went into atrial fibrillation which was reversed by IV aminophylline. Awareness of this uncommon effect of adenosine on the cardiac electrical pathways merits knowledge and a thorough follow-up testing of these patients is justified.

Pharmacomechanical Catheter-Directed Thrombolysis With the Bashir Endovascular Catheter for Acute Pulmonary Embolism: The RESCUE Study.

BACKGROUND: Catheter-directed thrombolysis (CDT) has been associated with rapid recovery of right ventricular (RV) function. The Bashir catheter was developed for enhanced thrombolysis in large vessels such as the pulmonary arteries (PAs) with lower doses of tissue plasminogen activator (tPA). OBJECTIVES: The aim of this study was to evaluate the efficacy and safety of tPA infused using a pharmacomechanical (PM) CDT device called the Bashir endovascular catheter in patients with intermediate-risk acute pulmonary embolism (PE). METHODS: Patients with symptoms of acute PE with computed tomographic evidence of RV dilatation were enrolled. The Bashir catheter was used to deliver 7 mg tPA into each PA over 5 hours. The primary efficacy endpoint was the core laboratory-assessed change in computed tomographic angiography-derived RV/left ventricular (LV) diameter ratio at 48 hours, and the primary safety endpoint was serious adverse events (SAEs) including major bleeding at 72 hours. RESULTS: At 18 U.S. sites, 109 patients were enrolled. The median device placement time was 15 minutes. At 48 hours after PM-CDT, the RV/LV diameter ratio decreased by 0.56 (33.3%; P < 0.0001). PA obstruction as measured by the refined modified Miller index was reduced by 35.9% (P < 0.0001). One patient (0.92%) had 2 SAEs: a retroperitoneal bleed (procedure related) and iliac vein thrombosis (device related). Two other procedure-related SAEs were epistaxis and non-access site hematoma with anemia. CONCLUSIONS: PM-CDT with the Bashir endovascular catheter is associated with a significant reduction in RV/LV diameter ratio and a very low rate of adverse events or major bleeding in patients with intermediate-risk acute PE. The notable finding was a significant reduction in PA obstruction with low-dose tPA. (Recombinant tPA by Endovascular Administration for the Treatment of Submassive PE Using CDT for the Reduction of Thrombus Burden [RESCUE]; NCT04248868).

First-in-Human Study to Assess the Safety and Feasibility of the Bashir Endovascular Catheter for the Treatment of Acute Intermediate-Risk Pulmonary Embolism.

BACKGROUND: The Bashir Endovascular Catheter (BEC) is a novel pharmaco-mechanical device designed to enhance thrombolysis by increasing the exposure of thrombus to endogenous and exogenous thrombolytics. The aim of this prospective, multicenter, single-arm study was to evaluate the feasibility and initial safety of the BEC in patients with acute intermediate-risk pulmonary embolism (PE). METHODS: Patients with symptomatic PE and right ventricular to left ventricular diameter ratio ≥0.9 as documented by computer tomography angiography were eligible for enrollment. The primary safety end points were device related death or adverse events, and major bleeding within 72 hours after BEC directed therapy. RESULTS: Nine patients were enrolled across 4 US sites. The total dose of r-tPA (recombinant tissue-type plasminogen activator) was 14 mgs in bilateral PE and 12 mgs in unilateral PE over 8 hours delivered via the expanded BEC. At 30-day follow-up, there were no deaths or device-related adverse events. At 48 hours post-BEC therapy, the right ventricular to left ventricular diameter ratio decreased from 1.52±0.26 to 0.97±0.06 (P=0.0009 [95% CI, 0.33-0.82]; 37.0% reduction). Thrombus burden as measured by the Modified Miller Index decreased from 25.4±5.3 to 16.0±4.0 (P=0.0005; [95% CI, 5.5-13.4]; 37.1% reduction). CONCLUSIONS: In this early feasibility study of the BEC for intermediate-risk PE, there were no deaths or device-related adverse events and a significant reduction in right ventricular to left ventricular diameter ratio and thrombus burden. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03927508.

Novel Micro Crown Orbital Atherectomy for Severe Lesion Calcification: Coronary Orbital Atherectomy System Study (COAST).

BACKGROUND: Percutaneous coronary intervention of severely calcified lesions carries a high risk of adverse events despite the use of contemporary devices. The Classic Crown Orbital Atherectomy System (OAS) was safe and effective for severely calcified lesion preparation in the ORBIT II study (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) but was not optimized for tight lesions. COAST (Coronary Orbital Atherectomy System Study) evaluated the safety and efficacy of calcified lesion preparation before stent implantation with the Diamondback 360 Micro Crown Coronary OAS, designed for use in tighter lesions. METHODS: COAST was a prospective, multicenter, single-arm study that enrolled 100 patients with severely calcified de novo coronary lesions at 17 sites in the United States and Japan. The primary effectiveness end point was procedural success, defined as stent delivery with residual stenosis <50% without in-hospital major adverse cardiac events (MACE), and the primary safety end point was freedom from MACE (composite of cardiac death, myocardial infarction, or target vessel revascularization) at 30 days. RESULTS: The OAS Micro Crown was inserted in all patients. A stent was delivered with a residual stenosis <50% in all except one patient (99.0%). Procedural success was achieved in 85 (85.0%) subjects versus 391 (88.9%) in ORBIT II (P=0.30), and freedom from MACE at 30 days was achieved in 85.0% versus 89.6% in ORBIT II (P=0.21). Freedom from MACE was 77.8% at 1 year. CONCLUSIONS: Prestent preparation of severely calcified lesions using the novel Micro Crown OAS resulted in similar rates of procedural success and freedom from MACE compared with the Classic Crown OAS. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02132611.

A Prospective, Single-Arm, Multicenter Trial of Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism: The SEATTLE II Study.

OBJECTIVES: This study conducted a prospective, single-arm, multicenter trial to evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis, using the EkoSonic Endovascular System (EKOS, Bothell, Washington). BACKGROUND: Systemic fibrinolysis for acute pulmonary embolism (PE) reduces cardiovascular collapse but causes hemorrhagic stroke at a rate exceeding 2%. METHODS: Eligible patients had a proximal PE and a right ventricular (RV)-to-left ventricular (LV) diameter ratio ≥0.9 on chest computed tomography (CT). We included 150 patients with acute massive (n = 31) or submassive (n = 119) PE. We used 24 mg of tissue-plasminogen activator (t-PA) administered either as 1 mg/h for 24 h with a unilateral catheter or 1 mg/h/catheter for 12 h with bilateral catheters. The primary safety outcome was major bleeding within 72 h of procedure initiation. The primary efficacy outcome was the change in the chest CT-measured RV/LV diameter ratio within 48 h of procedure initiation. RESULTS: Mean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs. 1.13; mean difference, -0.42; p < 0.0001). Mean pulmonary artery systolic pressure (51.4 mm Hg vs. 36.9 mm Hg; p < 0.0001) and modified Miller Index score (22.5 vs. 15.8; p < 0.0001) also decreased post-procedure. One GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries)-defined severe bleed (groin hematoma with transient hypotension) and 16 GUSTO-defined moderate bleeding events occurred in 15 patients (10%). No patient experienced intracranial hemorrhage. CONCLUSIONS: Ultrasound-facilitated, catheter-directed, low-dose fibrinolysis decreased RV dilation, reduced pulmonary hypertension, decreased anatomic thrombus burden, and minimized intracranial hemorrhage in patients with acute massive and submassive PE. (A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE) [SEATTLE II]; NCT01513759).

Pivotal trial to evaluate the safety and efficacy of the orbital atherectomy system in treating de novo, severely calcified coronary lesions (ORBIT II).

OBJECTIVES: The ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial evaluated the safety and efficacy of the coronary Orbital Atherectomy System (OAS) to prepare de novo, severely calcified coronary lesions for stent placement. BACKGROUND: Despite advances in interventional techniques, treatment of calcified coronary lesions remains a challenge. Stent placement in these lesions may result in stent underexpansion, malapposition, and procedural complications. METHODS: ORBIT II is a prospective, multicenter, nonblinded clinical trial that enrolled 443 consecutive patients with severely calcified coronary lesions at 49 U.S. sites from May 25, 2010, to November 26, 2012. Investigators used the centrifugal action of the OAS diamond-coated crown to modify calcified lesions prior to stent placement. RESULTS: The pre-procedure mean minimal lumen diameter of 0.5 mm increased to 2.9 mm after the procedure. The primary safety endpoint was 89.6% freedom from 30-day major adverse cardiac events compared with the performance goal of 83%. The primary efficacy endpoint (residual stenosis <50% post-stent without in-hospital major adverse cardiac events) was 88.9% compared with the performance goal of 82%. Stent delivery occurred successfully in 97.7% of cases with <50% stenosis in 98.6% of subjects. Low rates of in-hospital Q-wave myocardial infarction (0.7%), cardiac death (0.2%), and target vessel revascularization (0.7%) were reported. CONCLUSIONS: The ORBIT II coronary OAS trial met both the primary safety and efficacy endpoints by significant margins. Preparation of severely calcified plaque with the OAS not only helped facilitate stent delivery, but improved both acute and 30-day clinical outcomes compared with the outcomes of historic control subjects in this difficult-to-treat patient population. (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions [ORBIT II]; NCT01092416).

Acute coronary syndromes: unstable angina/non-ST elevation myocardial infarction.

Acute coronary syndrome is a major health problem affecting approximately 1.5 million individuals a year. Early diagnosis and appropriate evidence-based therapies improve clinical outcomes significantly. Current data suggest that an early invasive therapy may improve intermediate-term and long-term outcomes, particularly in high-risk individuals. The last few years also have seen significant advances in antiplatelet and antithrombotic therapies for the management of patients who have acute coronary syndrome.

Clinical outcomes in metabolic syndrome.

Metabolic syndrome is a clustering of cardiovascular risk factors. Its definition is the presence of any 3 of the following: obesity, hypertriglyceridemia, low high-density lipoprotein, hypertension, and impaired fasting glucose. The development of coronary artery disease is the most dreaded complication of this disease. In the United States, Mexican Americans and African American women are the most affected. Management of this syndrome includes physical exercise, weight loss, and effective drug treatment of dyslipidemia, high blood pressure, and impaired fasting blood glucose. Because of the increasing prevalence of obesity and diabetes, there is a rise in fatal and nonfatal cardiovascular events. With the development of effective antiplatelet medication and newer drug-eluting stents, percutaneous coronary intervention has become an effective revascularization strategy for those with coronary artery disease. Rates of stent restenosis and target-lesion revascularization have been reduced. Oral hypoglycemic drugs like thiazolidinediones improve insulin resistance and may have a favorable effect in those with metabolic syndrome. Diagnosis and appropriate management of metabolic syndrome are challenges as the presence of risk factors predates the coronary event.

Heart rate response during dipyridamole stress as a predictor of mortality in patients with normal myocardial perfusion and normal electrocardiograms.

Although it is well established that a blunted chronotropic response to exercise is associated with a higher risk of death, recent data suggest a similar association between mortality risk and blunted heart rate response to vasodilatory stress. We investigated the heart rate response to dipyridamole-induced stress as a predictor of death in the setting of normal myocardial perfusion and a normal electrocardiogram. We followed 1,087 patients for 8 years (range 5.7 to 11.8) who underwent dipyridamole vasodilator stress and had normal perfusion scans and electrocardiograms. None had heart failure, known left ventricular systolic dysfunction, pacemaker implantation, or valve disease. Heart rate response was assessed as the ratio of heart rate at peak stress to heart rate at rest. The primary end point was all-cause mortality. Quartile values for the peak-to-rest heart rate ratio were <1.19, 1.19 to 1.30, 1.31 to 1.44, and >1.44. There were 246 deaths. Death rates according to quartiles of heart rate ratio were 103 of 271 (38%), 64 of 272 (24%), 52 of 272 (19%), and 27 of 272 (10%). After adjusting for age, gender, heart rate at rest, blood pressure response, standard cardiovascular risk factors, and other confounders, a blunted heart rate response remained predictive of death (adjusted hazard ratio for lowest vs highest quartile 3.3, 95% confidence interval 2.1 to 5.1, p <0.0001). When considered as a continuous variable, the logarithm of the heart rate ratio was the strongest predictor of death, aside from age. Thus, among patients who have normal myocardial perfusion and normal electrocardiograms, a blunted heart rate response to vasodilator stress is predictive of a marked increase in risk of death.