Clinical, hemodynamic, electrocardiographic and mechanical events during nonocclusive, coronary atherectomy and comparison with balloon angioplasty

[Focus on high speed rotational atherectomy by Rotablator in 2021 and datas from France PCI registry]

Developed in the late 1980s, rotational atherectomy has raised a lot of hope for its innovative principle of selective ablation, allowing volume reduction (instead of redistribution) of atherosclerotic plaque, while sparing healthy tissue. Long shunned for its disappointing results on restenosis, the Rotablator finally reasserted itself in the 2000s; era of drug eluting stents and coronary angioplasty boom, thus generating emergence of complex lesions. Indeed, the Rotablator has demonstrated an undeniable benefit in complex (type C) and calcified lesions preparation (before stenting), with a procedural success rate of 95%. Although these lesions only represent a small amount (2-3%) of percutaneous coronary interventions (PCI), they remain a technical impasse for plain-old balloon angioplasty strategy, making the Rotablator more suitable for these resistant lesions' treatment. Registry data attest the safety of this therapy, with a rate of peri-procedural complications and in-hospital mortality comparable to conventional angioplasty (France PCI register). However, certain specific, rare but serious complications (burr entrapment, broken Rotawire, coronary perforation) justify trained teams, perfect knowledge of the equipment, and strict compliance with good practice guidelines. In 2018, the rise of a new method of atherectomy by intra-vascular lithotripsy (Shockwave) has coincided with Rotablator decreasing activity (this finding being biased by a general decrease in PCI activity due to Covid pandemic). This therapeutic range's enhancement revolutionizes calcified lesions treatment, tending towards precise targeting of each indication, depending in particular on calcium distribution's anatomy in the plaque.

[The indispensable instrument for rotational atherectomy]

Rotational atherectomy is the treatment of choice for calcified coronary lesions. It should not be used routinely but only in some appropriate cases, especially when the successful deployment of a stent may be uncertain. Complications are rare but serious. Several cases of "off label" use, however, have been reported in the literature without additional complications.

[Cardiac asystole during acute anterior myocardial infarction: a consequence of endocardiac reflexes]

The authors report a case of paroxysmal, complete atrioventricular block during an anterior acute myocardial infarction, leading to asystolia. The different possible physiopathological mechanisms are discussed, suggesting a paroxysmal nodal conduction defect, secondary to transient parasympathetic stimulation, triggered by a Bezold-Jarish type of cardiac reflex. This reflex is frequently involved in various pathologic situations or diagnostic procedures, usual in cardiology. Although it is frequently observed in inferior myocardial infarction, it can occur during an anterior acute myocardial infarction.

Reduced distal embolization with transluminal extraction atherectomy compared to balloon angioplasty for saphenous vein graft disease

Extraction atherectomy utilizes suction aspiration as an attempt to limit distal emboli during atherectomy. We sought to test the hypothesis that extraction atherectomy produces less distal embolization than balloon angioplasty when treating saphenous vein grafts. Among 163 consecutive, nonrandomized patients, 103 patients underwent transluminal extraction catheter (TEC) atherectomy with or without adjunctive balloon angioplasty, and 60 patients had conventional balloon angioplasty. Both groups showed comparably high procedural success rates (TEC 90.3%, angioplasty 83.3%, P = NS). TEC cases had a significantly lower incidence of angiographic distal embolization, compared with angioplasty (3.9% vs. 16.7%, P = 0.005). In cases with angiographic evidence of thrombus in the grafts, TEC maintained a significantly lower incidence of distal embolization than angioplasty (5.6% vs. 31.8%, P = 0.004). There were no statistical differences between the two groups regarding the incidence of other procedure-related complications, including death, myocardial infarction, or emergency coronary artery bypass grafting. TEC atherectomy appears to have a significantly lower incidence of distal embolization than balloon angioplasty when treating saphenous vein grafts, particularly in the presence of angiographically apparent thrombus.

Angiographic follow-up of patients after transluminal coronary extraction atherectomy

The transluminal coronary extraction-endarterectomy catheter (TEC) consists of a torquing tube with a distal, conical rotating blade. We successfully treated 26 patients (27 lesions) using this catheter with adjunctive balloon angioplasty. Twenty-five patients (26 lesions) had serial angiography before, 1 day after, and 3 months after the procedure. All 17 patients without restenosis 3 months after the procedure had angiography at 6 months. Restenosis, defined as > 50% diameter stenosis, was noted in nine lesions at 3 months (early restenosis) and in five lesions at 6 months (late restenosis). Between vessels with and without early restenosis, the percentage of diameter stenosis seen 1 day after the procedure and the luminal diameter were significantly different (38% +/- 14% vs 22% +/- 12%, respectively, p < 0.01; 2.3 vs 2.9 mm, p < 0.01, respectively). However, between vessels with and without late restenosis, these variables were not significantly different. The overall restenosis rate was 54% (native vessels 50%; grafts 80%). This observational study suggests that very early diameter narrowing seen 1 day after the procedure has greater contribution to early restenosis than to late restenosis after successful TEC atherectomy with adjunctive balloon angioplasty.

Intravascular ultrasound imaging after excimer laser angioplasty

To help elucidate the mechanism of excimer laser coronary angioplasty (ELCA), intravascular ultrasound (IVUS) imaging was performed in 19 of 29 patients who were treated with ELCA. The results were compared with a non-randomized control group of 18 patients who had IVUS studies both before and after PTCA alone. After ELCA alone, lumen diameter (1.9 x 1.7 mm) and lumen cross-sectional area (CSA) (2.9 mm2) by IVUS were not significantly different from baseline values in the patients before PTCA alone (2.1 x 1.8 mm, 3.2 mm2). After balloon dilatation in the laser treated group, lumen diameter (2.5 x 2.1 mm) and lumen CSA (4.9 mm2) were significantly greater than those post ELCA alone. However, there was no difference in lumen CSA or atheroma CSA in the group treated with excimer laser plus balloon dilatation vs. these measurements in the group treated with PTCA alone. ELCA does not ablate a large amount of atheroma (9% reduction) but creates a pathway to permit easier passage of a PTCA balloon. These quantitative and morphologic results may help explain why the restenosis rate with ELCA is similar to PTCA alone.