Rheolytic Thrombectomy via Radial Artery Access to Treat ST-Elevation Myocardial Infarction

Case

A 69-year-old male with no significant past medical history presented to the emergency department with an acute onset of chest pain. The electrocardiogram revealed inferior wall ST-segment elevation myocardial infarction (STEMI). The patient was hemodynamically stable and emergently transported to the cardiac catheterization suite for primary percutaneous coronary intervention (PCI). The procedure was performed through the right radial artery utilizing a 6-French Glidesheath (Terumo Corporation). Initial angiography revealed a large, ectatic right coronary artery (RCA) with a proximal sub-total occlusion and TIMI II distal flow. A large (approximately 4 mm x 15 mm) filling defect consistent with a thrombus was visualized just distal to the stenosis (Figures 1-2). Angiography of the left coronary system revealed mild, non-obstructive disease with ectasia of the left anterior descending artery.

After visualization of the RCA, the initial JR 4 guide was exchanged for a more supportive 6 French MAC 3.0 guide (Medtronic). A Kinetix moderate support wire (Boston Scientific) was used to cross the lesion and inserted into the distal right posterior descending artery (RPDA). A 4 French Spiroflex rapid exchange AngioJet catheter (Medrad) was used to perform rheolytic aspiration thrombectomy with multiple passes (Figure 3). The door-to-thrombectomy time was 51 minutes. The AngioJet catheter was then removed and 200 mcg of intracoronary nicardipine injected. The lesion was predilated with a 4.0 mm x 15 mm NC Quantum Apex Monorail balloon (Boston Scientific). Slow flow was visualized and 300 mcg of intracoronary nicardipine was again injected. A 4.5 mm x 15 mm Veriflex Monorail bare-metal stent (Boston Scientific) was then deployed at 16 atm pressure to 5.0 mm (Figure 4). The stent was post-dilated using a 5 mm non-compliant balloon. An excellent angiographic result was achieved with 0% residual stenosis and TIMI-3 flow (Figure 5). The patient had an uncomplicated hospital course and was discharged to home 56 hours after the index event. Dual antiplatelet therapy [aspirin and prasugrel (Effient, Eli Lilly)] was continued upon discharge.

Discussion

The use of radial artery access for primary PCI in the setting of STEMI was initially met with some skepticism, mainly due to concerns surrounding prolongation of door-to-balloon times. The literature, however, has not validated this concern and radial artery access is becoming increasingly common during emergent PCI.^1-3 Furthermore, in the treatment of acute STEMI, radial artery access may offer the best opportunity for improving mortality and morbidity compared to femoral access. Pre-specified, subgroup analysis of patients with STEMI in the RIVAL (RadIal V. femorAL for coronary intervention) study showed significant improvement in the rate of bleeding complications as well as mortality with the transradial approach over transfemoral approach.¹ Vorobcsuk et al² performed a systemic review of twelve randomized, case-control and cohort studies involving 3,324 patients, comparing access-related complications in STEMI. Transradial PCI reduced major bleeding compared to transfemoral PCI (0.77% vs 2.61%, OR 0.30, P = .0001), and significantly reduced mortality (2.04% vs 3.06%, P = .01). In this analysis, the door-to-balloon time was slightly better in the transradial group. These studies involved very experienced radial operators and high-volume radial centers. Analysis of door-to-balloon times in our practice revealed similar results.³ Particularly for rescue PCI after failed thrombolytics and in patients loaded upfront with glycoprotein IIb/IIIa inhibitors, radial access provides an additional benefit.

With the miniaturization of devices, it is possible to get most primary PCI equipment through a 6 Fr system. Our patient had a very high thrombus burden and was treated with rheolytic aspiration thrombectomy through a 6-French guide.

The following tips may help readers establish a successful transradial primary PCI program:

1. A transradial primary PCI program should be initiated only after acquiring adequate experience by both the operator and the catheterization lab team.  According to experts4, experience of at least 250 diagnostic transradial catheterizations and 75 PCIs are needed before starting a primary PCI program. 
2. Only hemodynamically stable patients should be included in the early stages of a transradial primary PCI program.
3. In stable patients undergoing elective complex PCI, radial artery access should be attempted to increase operator and team experience.
4. Always prepare the groin in anticipation of the possible need for balloon pump placement, trans-venous pacemaker insertion, or the need to switch to femoral access.
5. When faced with a roadblock at any level (e.g., difficulty accessing the radial artery, radial loop, and severe subclavian tortuosity) transition to femoral artery access should be immediately considered in order to maintain optimal door-to-balloon times. Performance review after each case during the initial 25 cases is advised.
6. Elderly, female patients, particularly those with a low body mass index, are better approached through left radial, as tortuosity of the innominate artery is more prevalent in this population.
7. If a patient has a left internal mammary artery (LIMA) to left anterior descending coronary artery (LAD) bypass graft, the left radial should be used, if possible. If not possible, femoral access should be utilized.
8. The choice of pharmacotherapy, catheter and other devices are, of course, at the discretion of the individual operator. Our workhorse guides are the JR 4 and EBU 3.5. Whenever guide support is crucial, we prefer MAC 3.0 for the RCA. Depending on the operator’s experience, a universal guide catheter such as a Tiger (Terumo) or PaPa (Medtronic) can be used to avoid catheter exchange time.

The authors can be contacted via Dr. Kintur Sanghvi at: SanghviK@Deborah.org

Disclosure: The authors report no conflicts of interest regarding the content herein.

References

1. Jolly SS, Yusuf S, Cairns J, Niemelä K, et al; RIVAL trial group. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet 2011 April; 377(9775): 1409-1420.
2. Vorobcsuk A, Kónyi A, Aradi D, Horváth IG, Ungi I, Louvard Y, Komócsi A. Transradial versus transfemoral percutaneous coronary intervention in acute myocardial infarction: systematic overview and meta-analysis. Am Heart J 2009 Nov; 158(5): 814-821.
3. Pancholy S, Patel T, Sanghvi K, Thomas M, Patel T. Comparison of door-to-balloon times for primary PCI using transradial versus transfemoral approach. Catheter Cardiovasc Interv 2010 Jun 1; 75(7): 991-995.
4. Patel T, Pyne C, Shah S, Pancholy S. TRA for acute myocardial infarction (AMI) interventions. In: Patel T, Pancholy S, Shah S, eds. Patel’s Atlas of Transradail Intervention: The Basics and Beyond. 2nd ed. Malvern, PA: HMP Communications; 2012: 133.