Percutaneous transluminal septal artery ablation using polyvinyl alcohol foam particles for septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: acute and 3-year outcomes.

PURPOSE: To investigate the effect of septal artery occlusion with transluminally delivered polyvinyl alcohol (PVA) foam particles for the treatment of hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Percutaneous septal artery ablation was performed in 18 symptomatic patients (13 men; mean age 60+/-17 years, range 28-89) with drug-resistant HOCM. PVA foam particles were mixed with contrast medium and injected through an angiographic catheter under fluoroscopic control until complete stasis in the septal branch was achieved. Patients were monitored with echocardiography and cardiovascular magnetic resonance imaging. RESULTS: The septal artery was successfully occluded in all patients; no embolization of other coronary branches occurred after infusion of 3 to 8 mL (5.2+/-0.8) of PVA foam particles. The resting pressure gradient was diminished from 83+/-32 to 31+/-35 mmHg (p<0.05). Over a mean follow-up of 44+/-4 months, all patients had symptomatic improvement of their dyspnea and workload without the need for intensified drug therapy. The average NYHA functional class decreased from 3.3+/-0.5 to 1.3+/-0.7 (p<0.0001), with a significant increase in the area of the left ventricular outflow tract (1.3+/-0.2 to 2.6+/-0.2 cm2, p<0.0001). Three instances of transient atrioventricular block occurred, but no complete heart block was produced by the embolization procedure. CONCLUSIONS: Embolization of the septal artery with PVA foam particles appears effective and safe in this series of patients with hypertrophic obstructive cardiomyopathy. The pure ischemic infarction produced by PVA ablation might be the responsible for the lack of complete heart block and the need for permanent pacing.

Cardiovascular magnetic resonance of acute myocardial infarction at a very early stage.

OBJECTIVES: Very early changes in myocardial tissue composition during acute myocardial infarction (AMI) are difficult to assess in vivo. Cardiovascular magnetic resonance (CMR) imaging provides techniques for visualizing tissue pathology. BACKGROUND: The diagnostic role of CMR in very acute stages of myocardial infarction is uncertain. We investigated signal intensity changes beginning within 60 min after acute coronary occlusion in patients undergoing therapeutic septal artery embolization. METHODS: We investigated eight patients with hypertrophic obstructive cardiomyopathy undergoing interventional septal artery embolization by applying microparticles to reduce left ventricular outflow tract obstruction. In a clinical 1.5-tesla (T) CMR system, we visualized infarct-related myocardial signal by T(1)-weighted sequences before and 20 min after administration of contrast media (delayed enhancement) and edema-related signal by T(2)-weighted spin-echo sequences before and 58 +/- 14 min after the intervention as well as on days 1, 3, 7, 14, 28, 90, and 180 during follow-up. RESULTS: Infarct-related changes as defined by contrast enhancement were observed as early as 1 h after the intervention and during six months of follow-up. In contrast, infarct-related myocardial edema, as visualized by high signal intensity in T(2)-weighted spin-echo sequences, was not consistently detectable 1 h after acute arterial occlusion; this was possible in all subsequent studies until day 28. CONCLUSIONS: Contrast-enhanced magnetic resonance imaging detected infarct-related signal changes as early as 1 h after AMI in humans, whereas the sensitivity of edema-related signal changes was not sufficient during this very early stage.

Quantification of valvular aortic stenosis by magnetic resonance imaging.

BACKGROUND: Assessing the aortic valvular orifice is important in judging the severity of aortic stenosis. Magnetic resonance imaging visualizes in-plane valvular motion. We studied the value of magnetic resonance planimetry of the aortic valve orifice. METHODS: We used breath-hold gradient echocardiographic sequences on a clinical magnetic resonance system (1.5 T) and studied 25 patients with symptomatic valvular aortic stenosis. We performed a planimetry of the valvular orifice in systolic images of the valvular plane. The results were compared with echocardiography (continuity equation) and cardiac catheterization (Gorlin formula). RESULTS: Magnetic resonance planimetry was feasible in all patients, and the image quality was invariably adequate. The magnetic resonance imaging results correlated well with the data calculated from catheterization and less robustly with the echocardiographic results. The 3 methods were similar in terms of leading to clinical decisions. CONCLUSIONS: We suggest that magnetic resonance flow planimetry of the aortic valve orifice offers a simple, reliable, fast, and safe method to noninvasively quantify aortic stenosis.