“Stuck Between a Rock and a Hard Place”: Rotational Atherectomy in STEMI

Plaque modification by rotational atherectomy (RA) in setting of ST-elevation myocardial infarction (STEMI) has been controversial and remains a contraindication by the manufacturer. As the U.S. population continues to age, the prevalence of calcified atherosclerotic morphology will continue to increase and atherectomy will be a vital tool in this complex subset. But the situation where a difficult, calcified stenosis acutely closes offers a unique interventional dilemma. Initial reports have demonstrated feasibility and we present the case of a man who presented with an inferior STEMI that required RA for successful intervention of a heavily calcified right coronary artery (RCA).^1,2

 

 

A 58-year-old man presented with acute sub-sternal chest pain while at home. The patient had been seen 8 months prior with worsening angina and found to have severely calcified three-vessel disease, including a 60% severely calcified RCA (Figure 1, Online Video 1), and was turned down by cardiothoracic surgery for bypass due to poor functional status and ongoing substance abuse. The decision was made to pursue conservative medical management and uptitrate anti-anginal therapy. Electrocardiogram on presentation noted ST elevations in inferior leads (II, III, aVF) with reciprocal ST segment changes in anterior leads and the patient was taken emergently to the catheterization lab (Figure 2). After a quick review of previous films and due to anticipated need for RA, femoral access with a 7 French arterial sheath was performed. Diagnostic catheterization confirmed a 100% acutely occluded, heavily calcified mid RCA stenosis (Figure 3, Online Video 2). The patient was anticoagulated to goal activated clotting time (ACT) >300 with intravenous heparin and a 7 French Amplatz Left (AL) 0.75 guide catheter was used to engage the RCA. An .014-inch Choice PT ES Wire (Boston Scientific) was used to cross the lesion and a Trek OTW 2.00 x 15 mm balloon (Abbott Vascular) was used to pre-dilate the mid and distal RCA with reconstitution of TIMI-3 flow (Figure 4, Online Video 3). A temporary pacemaker was placed at the right ventricular apex and the Choice PT ES wire was exchanged for a RotaFloppy wire (Boston Scientific). Two runs of rotational atherectomy with the Rotablator catheter (Boston Scientific) were performed at 140,000 rpm with a 1.5 burr for 10-15 seconds (Figure 5, Online Video 4). Repeat angiography noted no evidence of slow/no reflow or perforation. A Finecross microcatheter (Terumo) was then used to exchange for an All-Star guide wire (Abbott Vascular) and intravascular ultrasound (IVUS) was performed for vessel sizing. A 2.5 x 15 mm semi-compliant balloon was inflated serially to 14 atmospheres (atm) for pre-dilation, then a 3.0 x 15 mm Chocolate balloon (TriReme Medical) was inflated up to 15 atm (Figure 6). A 6 French Guideliner (Vascular Solutions) was then used to assist positioning of a 3.25 x 33 mm Xience Alpine drug-eluting stent (Abbott Vascular) which was deployed at 16 atm, then post-dilated with a 3.50 x 15 mm non-compliant Trek balloon (Abbott Vascular) to 18 atm. Post intervention angiography noted excellent angiographic result with no residual stenosis, dissection or distal wire perforation (Figure 7, Online Video 5). IVUS noted well apposed, well expanded stent struts with no evidence of geometric miss, tissue prolapse, or edge dissection (Figure 8).

 

 

RA in STEMI remains contraindicated by the manufacturer due to concerns of increased risk of platelet activation in the inflammatory milieu, and an increased occurrence of no or slow reflow.  Previous evaluation noted RA in acute coronary syndrome (ACS) to have similar low complication rates compared to RA in non-ACS indications. Doshi et al retrospectively evaluated 1112 patients who underwent RA and noted that, of the 269 patients with ACS who underwent RA, that they had similar major complication rates and adverse cardiovascular event rates at 30 days compared to non-ACS RA intervention. But utility of RA in STEMI has not been well evaluated and remains a difficult decision. Initial reports have demonstrated feasibility and, despite the theoretical risks, an aggressive approach is required in this challenging circumstance for optimal results.^1,2 Fundamental tenets to reduce the risk of adverse events in RA include a conservative burr-to-artery ratio of <0.5-0.6, maintaining adequate rotational speed at 140-160,000 rpm, avoiding decelerations >5,000 rotations per minute (rpm), short burr runs, as well as optimal peri procedural anticoagulation and antiplatelet therapy. Temporary pacing was employed as standard practice for RA of RCA lesions and added minimal time to the intervention, as the decision was made to pursue femoral venous access upfront due to an anticipated need for RA in this instance. The use of the Chocolate balloon for lesion preparation allowed for a conservative burr-to-artery ratio and provided excellent lesion expansion after RA with minimal dissection/embolization. It was felt that optimal stent expansion and apposition could not have been achieved without plaque modification in this instance.

 

 

This case presents a novel solution to the difficult dilemma of STEMI superimposed on a severely calcified lesion. The authors agree that RA in the setting of visible thrombus with <TIMI-2 flow may be hazardous, but if reconstitution of TIMI-3 flow is successful, then plaque modification via RA should be considered in appropriate clinical circumstances.