Chocolate CHIP Intervention Reloaded: Rotational Strikes Back!

A 69-year-old male presented with fatigue, dyspnea, dizziness, and palpitations after mowing the lawn. Electrocardiogram (ECG) showed slow ventricular tachycardia (VT) (Figure 1). He had a similar episode 6 months earlier (thought to be scar VT) that was treated with cardioversion and intensified beta blockade. His past medical history is significant for:

1)    Ischemic cardiomyopathy with an ejection fraction (EF) of 25-30%:

• ICD (implantable cardioverter-defibrillator) implantation in 2001;
• Most recent cardiac catheterization in 2001 revealed an occluded distal right coronary artery (RCA);
• Non-viable inferior/inferolateral walls (with aneurysm, confirmed by cardiac magnetic resonance imaging);

2)     Chronic kidney disease, stage 3A;
3)     Hypertension; 
4)     Hyperlipidemia.

Physical examination was unremarkable other than a laterally displaced apex beat at the anterior axillary line.

Transthoracic echocardiography images can be seen in Figure 2 (Videos 1-4). Left heart catheterization was repeated and revealed occlusion of the RCA, and severely calcified and hemodynamically significant proximal left anterior descending artery (LAD) coronary artery disease with fractional flow reserve (FFR) of 0.55 and a minimal lumen area (MLA) of 2.7 mm² by intravascular ultrasound (IVUS) (Figure 3, Videos 5-7). In view of the heavy calcification in the proximal LAD segment, any percutaneous attempt would necessitate atherectomy.

We considered the following treatment options in this patient:

1. Coronary artery bypass grafting (CABG) with left internal mammary artery (LIMA) to the LAD with aneurysmectomy;
2. CABG with LIMA to the LAD only;
3. Percutaneous coronary intervention (PCI) to the LAD.

The patient was turned down by cardiac surgery for an aneurysmectomy and was offered LIMA-LAD alone, but the patient refused and instead opted for PCI. 

Using micropuncture technique with fluoroscopic guidance, a 6 French (Fr) sheath was placed in the right common femoral artery. Using a 5 Fr diagnostic internal mammary artery (IMA) catheter, “roadmapping” was performed of the left common iliac artery and its branches. Using micropuncture technique, access was obtained in the left common femoral artery and a percutaneous left ventricular assist device (LVAD), the Impella 2.5 (Abiomed), was placed via a 13 Fr sheath in the left common femoral artery into the left ventricle (LV) after initially placing a 5 Fr pigtail catheter in the LV and exchanging this over an .018-inch guide wire (Figure 4, Video 8). The left ventricular end diastolic pressure (LVEDP) was measured at 13 mm Hg. Therapeutic anticoagulation was achieved with intravenous heparin.

A 6 Fr Extra Backup (EBU) 3.75 guide (Medtronic) was exchanged and the left main was engaged. The previously discussed FFR (0.55) and IVUS (MLA 2.7 mm²) measurements were performed at this point. The ostial left circumflex coronary artery (LCX) was also assessed and found to have a MLA of 8.0 mm². A 180 cm, .014-inch Whisper wire (Abbott Vascular) was used via a 1.5 x 6 mm Sprinter over-the-wire (OTW) balloon (Medtronic) to wire the LAD with moderate difficulty, and this was exchanged for a 330 cm, .014-inch RotaWire Floppy guide wire (Boston Scientific). Four passes of rotational atherectomy (Boston Scientific) were performed using a 1.5 mm burr at 144,000 rpm (Figure 5). Using the same OTW balloon, the Rota-Floppy wire was exchanged for a 300 cm, .014-inch All Star guide wire (Abbott Vascular). A 2.5 mm x 20 mm Chocolate balloon (Trireme Medical, LLC) was used to pre-dilate the lesion at a peak inflation pressure of 14 atmospheres (atm) for 20 seconds (Figure 6). Further lesion preparation was necessary at the proximal area with a 3 mm x 20 mm Chocolate balloon at a peak inflation pressure of 14 atm for 20 seconds. Subsequently, a 2.5 mm x 38 mm Promus Premier drug-eluting stent (Boston Scientific) was deployed at a peak inflation pressure of 16 atm for 30 seconds (Figure 7). It was post-dilated distally with a NC Trek 2.5 mm x 20 mm balloon (Abbott Vascular) at a peak inflation pressure of 16 atm for 20 seconds and proximally with a 3 mm x 15 mm NC Sprinter balloon at a peak inflation pressure of 20 atm for 20 seconds (Figure 8).

Final angiography demonstrated excellent results with TIMI-3 flow, without distal embolization, perforation, or dissection (Figure 9). The final IVUS MSA was 6.5 mm² in the proximal LAD. Following successful high-risk PCI with Impella 2.5 support to the ostial/proximal LAD, the Impella device was removed with no complications and the access site was sealed with two Perclose ProGlide closure devices (Abbott Vascular). The right common femoral artery was sealed with a 6 Fr Angio-Seal closure device (St. Jude Medical) and the patient was uneventfully discharged back to his room. He is doing well at 6-month follow-up with no subsequent episodes of VT.

The following measures enabled procedural success and a great outcome:

1.  Patient selection

Appropriate patient selection is essential for the success of any procedure. A heart team approach was undertaken to ensure that risks and benefits of alternative treatments and surgeries were considered. Shared decision making with the patient was undertaken to ensure that patient preferences were incorporated into the final choice. Magnetic resonance imaging was obtained to confirm the large inferior and infero-lateral scars that would not benefit from revascularization and to confirm the viability of the anterior wall, which would benefit from revascularization.

2. Hemodynamic support

In our experience in patients with decreased LV systolic function, adequate hemodynamic support with a percutaneous LVAD goes a long way to enable success and promote safety, especially when atherectomy is required.
In a subgroup analysis of 52 patients (32 with Impella 2.5 vs 20 with an intra-aortic balloon pump [IABP]) who underwent rotational atherectomy in the PROTECT II trial, Cohen et al¹ reported that these patients were more likely to have severely calcified arteries compared to those who did not undergo rotational atherectomy 44.2% vs 12.1% (P<0.001). There were a total of 14 myocardial infarctions (MI) in patients undergoing rotational atherectomy, 12 of which were periprocedural (11 with Impella and 1 with IABP) and 2 were spontaneous (1 with Impella and 1 with IABP). Patients who experienced a periprocedual MI had longer rotational atherectomy time, and tended to be treated with slightly higher burr sizes and more passes per patient and per lesion, compared to those without periprocedural MI. Rotational atherectomy was used more aggressively with Impella, resulting in higher rate of periprocedural MI (P<0.01), and there was no difference in mortality between groups (P=0.78).

3. Plaque modification equipment

Severe calcification remains a significant barrier to feasibility, decreases procedural success, increases complications, and worsens long-term outcomes following PCI. However, being facile with various plaque modification equipment, i.e., atherectomy and specialty balloons, can improve success rates and enhance patient safety. Rotational atherectomy functions by “differential cutting,” whereby noncompliant areas (e.g., calcified or fibrous lesions) are selectively ablated and more elastic areas are not. As we have discussed earlier, in the March issue of Cath Lab Digest², there are significant synergies that can be exploited when utilizing different plaque modification equipment. Here, we have demonstrated that rotational atherectomy with adjunctive Chocolate balloon angioplasty facilitates excellent stent expansion and apposition, and will hopefully decrease the risk of restenosis and thrombosis in this very calcified LAD.

References

1. Cohen MG, Ghatak A, Kleiman NS, Naidu SS, Massaro JM, Kirtane AJ, et al. Optimizing rotational atherectomy in high-risk percutaneous coronary interventions: insights from the PROTECT II study. Catheter Cardiovasc Interv. 2014 Jun 1; 83(7): 1057-1064. doi: 10.1002/ccd.25277.
2. Marrero O, Desai R, Kumar G. Chocolate CHIP* intervention: an orbital experience. Cath Lab Digest. 2016 Mar; 24(3). Available online at https://www.cathlabdigest.com/article/Chocolate-CHIP-Intervention-Orbital-Experience. Accessed May 23, 2016. 

Disclosures: Dr. Rupak Desai and Bernetta Howard report no conflicts of interest regarding the content herein. Orlando Marrero reports he is an employee of Boston Scientific. Dr. Gautam Kumar reports one consulting event with Abiomed, one consulting event with Cardinal Health, and one consulting event with CSI Medical in the last 12 months. 

Orlando Marrero, RCIS, MBA, can be contacted at orlm8597@icloud.com. 

Dr. Gautam Kumar can be contacted at gautam.kumar@emory.edu.