Transradial Alcohol Septal Ablation

ABSTRACT: Radial access is shown to have fewer access-related complications when compared to femoral artery access. While two small European studies have examined the feasibility of transradial access for alcohol septal ablations, no reports from the United States have yet been published. We report the case of a 69-year-old male with hypertrophic cardiomyopathy who underwent alcohol septal ablation via the right radial artery approach and discuss the technique. 

J INVASIVE CARDIOL 2014;26(4):E37-E39

Key words: access-site complications, transradial approach

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The popularity of the transradial approach for coronary catheterizations and interventions has increased significantly. Between 2004 and 2007, the radial approach accounted for only 1.32% of all percutaneous coronary interventions performed in the United States.¹ In April 2012, more than 11% of coronary interventions are performed via radial approach. This increase in a relatively short period is mainly driven by similar success rates as the femoral approach, but with reduced risk of bleeding, especially in patients over 75 years, women, and patients presenting with acute coronary syndromes.¹ The radial approach is also increasingly considered for non-coronary procedures including endovascular procedures.^2-4 Further exploration is needed for using radial access for structural heart interventions.

Case Report. A 69-year-old male patient presented with progressive angina on exertion. His past medical history consisted of coronary artery disease with previous left anterior descending (LAD) intervention, hypertrophic cardiomyopathy (HCM), and atrial fibrillation. He had a pacemaker placed as part of a National Institutes of Health study examining pacing in HCM, but this was later upgraded to an implantable cardiodefibrillator (ICD) after an episode of ventricular tachycardia. His daily medications included carvedilol 25 mg twice daily, verapamil ER 180 mg daily, and amiodarone 100 mg daily. Four weeks prior, he was admitted with Canadian Cardiovascular Class III angina. During left heart catheterization, a manual pullback performed without the use of a dual-lumen catheter in the left ventricle (LV) revealed a 30 mm Hg intracavitary gradient. His LAD coronary artery had an angiographically flow-limiting stenosis, which was treated with a drug-eluting stent. This was felt to be the cause of the patient’s angina. He was discharged home the next day after LAD stenting.

The patient again presented on this current admission with angina while mowing his lawn. The chest pressure was more severe and persisted longer than his previous anginal discomfort. In addition, he had chest pressure after climbing two flights of stairs. Due to his repeat symptoms, he was brought back to the cardiac catheterization laboratory. Catheterization was performed via the right radial artery. A 6 Fr radial Glidesheath (Terumo Corporation) was placed after arterial access was obtained using an Introcan Safety IV cannula (B. Braun). After sheath placement, a combination of 200 µg nitroglycerin and 2.5 mg verapamil was given intraarterially. Ninety U/kg heparin was given intravenously after the catheter was in the ascending aorta.

Angiography demonstrated patency of the previously placed stents. A Langston dual-lumen multipurpose catheter (Vascular Solutions) was placed in the left ventricular apex and aortic root and revealed a 50 mm Hg gradient with the Valsalva maneuver. A premature ventricular contraction (PVC) induced by the catheter led to a 100 mm Hg peak gradient in the post-PVC beat (Figure 1). Echocardiography performed prior to the procedure suggested the diagnosis of hypertrophic cardiomyopathy. There was mild systolic anterior motion of the mitral valve with mild mitral regurgitation. Measured septal thickness was 2.1 cm. Despite a non-significant intracavitary gradient at rest, with Valsalva maneuver there was a 49 mm Hg intracavitary Doppler gradient (Figure 2). The left ventricular pressures with the dual-lumen catheter confirmed the echocardiographic findings.

With his continued symptoms of angina despite his medical therapy, we proceeded with alcohol septal ablation treatment. A 6 Fr EBU 3.5 Launcher guide (Medtronic, Inc.) was used to engage the left coronary system. A 300 cm Asahi Prowater wire (Abbott Vascular) was placed in the first septal perforator artery. A 1.5 x 6 mm over-the-wire Sprinter balloon (Medtronic, Inc.) was inflated to 14 atm in the proximal portion of the first septal perforator (Figure 3). Initially, contrast was injected through the balloon to ensure no contrast spilling into the LAD. Using echocardiographic guidance, agitated saline was also injected through the balloon to confirm that the same septal branch perfused the hypertrophied myocardium. One milliliter of alcohol was slowly injected over a minute through the balloon. This was repeated every minute for a total of 3 mL of alcohol. Prior to balloon deflation, contrast was injected through the balloon and guide catheter to again confirm containment in the septal artery without spillover. The balloon was inflated for a total duration of 9 minutes. The balloon and guiding catheter were removed. During the procedure, the patient had no rhythm disturbances, but it is important to note that he did have a pacemaker. He did experience chest discomfort following the injection of the alcohol.

Following removal of the guiding catheter, the dual-lumen multipurpose catheter was reinserted in the left ventricle. The left ventricular gradient was remeasured and showed improvement. Postprocedure troponin peaked at 13.7 µg/L with a maximum creatinine kinase of 948 U/L. Echocardiography performed the next day demonstrated a 39 mm Hg gradient. The following day, he was discharged home. He was seen at follow-up 3 months later and stated he was asymptomatic and doing well. An echocardiogram performed at that visit revealed a 5 mm Hg gradient in the left ventricle.

Discussion. Hypertrophic cardiomyopathy is an autosomal dominant trait characterized by a thickened but non-dilated left ventricle not caused by another condition, either cardiac or systemic.⁵ It is estimated to occur in 0.2% of the general population.⁶ One-third of patients will have obstruction at rest, one-third will have obstruction with provocation, and one-third will have non-obstruction.⁷ When assessing hypertrophic cardiomyopathy, it is the peak gradient, not the mean gradient that determines treatment plans5 Gradients greater than or equal to 50 mm Hg either at rest or with provocation represent the point at which intervention may be considered.⁵ Other criteria that must be met are symptoms such as dyspnea, chest pain, or other exertional symptoms that interfere with daily life and a septal thickness that is sufficient to perform the procedure safely.⁵ Beta-blockers are the first line of therapy,^5,8 but septal reduction therapy may be considered in patients who fail medical therapy.⁵ Meta-analyses have demonstrated an improvement in hemodynamic and functional status with both surgical and endovascular muscle reduction modalities.^9,10 Guidelines exist that suggest younger patients may benefit more from surgical myectomy, whereas older patients may benefit more from alcohol septal ablation.⁵

While much discussion regarding the appropriateness of the two septal reduction therapies, little has been discussed about the treatment approach for alcohol septal ablation. Radial access for cardiac catheterizations has been shown to reduce adverse events including bleeding when compared to the femoral approach, as well as trending toward lower rates of myocardial infarction and death.¹¹ Radial access is also preferred by patients and leads to increased patient satisfaction.¹² A small study of 30 patients was performed in France to assess the feasibility of the transradial approach for alcohol septal ablation, and found no complications related to the procedure.¹³ This report also suggests that alcohol septal ablation can be performed safely through the radial approach. A similar study by Polansky et al also showed the feasibility of transradial alcohol septal ablation in 43 patients.¹⁴

Pacing support can be performed via the arm as well. Werner Forssman, in 1929, performed the first right heart catheterization from the arm. The temporary pacing lead can be placed using the same techniques as right heart catheterization. Either the basilic or cephalic vein can be utilized, although due to anatomic considerations, the basilic vein allows for easier access to the central venous system. The cephalic vein enters the axillary vein perpendicular to the course of the axillary vein. In addition, the bleeding risk is similarly reduced with access via the upper-extremity venous system as it is with arterial access. The venous system is not a high-pressure system, and thus compression devices are not needed.¹⁵ In both the French study and the study performed by Polansky et al, the pacing lead was placed in the subclavian vein.^13,14 Another alternative for placement of the pacing lead is the jugular vein.  

Crossing a non-stenotic aortic valve with a pigtail catheter is a common occurrence when performing a left heart catheterization. From the radial approach, it relatively easy to cross the valve with a JR 4 or multipurpose catheter and a standard J-tipped 0.035˝ wire. The catheter is placed in the ascending aorta, and directed toward the valve. The wire is advanced and coiled in the left cusp until it prolapses into the ventricle. In addition, the catheter itself can be coiled in the cusp in a technique similar to crossing the valve with a pigtail catheter. In the reported case, we initially missed the diagnosis by measuring a pullback gradient using a single-lumen catheter. When evaluating a patient for hypertrophic cardiomyopathy, a dual-lumen multipurpose catheter is recommended to provide an accurate gradient across the hypertrophied portion of the left ventricle.

Conclusion. It is feasible to perform alcohol septal ablation via radial artery access with careful planning. This approach needs further evaluation to compare the benefit and limitations versus the traditional approach.

References

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10. Alam M, Dokainish H, Lakkis NM. Hypertrophic obstructive cardiomyopathy — alcohol septal ablation vs. myectomy: a meta-analysis. Eur Heart J. 2009;30(9):1080-1087.
11. Jolly SS, Amlani S, Hamon M, et al. Radial versus femoral access for coronary angiography or intervention and the impact on major bleeding and ischemic events: a systematic review and meta-analysis of randomized trials. Am Heart J. 2009;157(1):132-140.
12. Cooper CJ, El-Shiekh RA, Cohen DJ, et al. Effect of transradial access on quality of life and cost of cardiac catheterization: a randomized comparison. Am Heart J. 1999;138(3 Pt 1):430-436.
13. Cuisset T, Franceschi F, Prevot S, et al. Transradial approach and subclavian wired temporary pacemaker to increase safety of alcohol septal ablation for treatment of obstructive hypertrophic cardiomyopathy: the TRASA trial. Arch Cardiovasc Dis. 2011;104(8-9):444-449.
14. Polansky BM, Stasek J, Bis J, et al. The effectiveness and safety of alcohol septal ablation performed transradially. Paper presented at AIM Radial 2012; September 13, 2012 in Quebec City, Canada.
15. Gilchrist IC. Radial approach to right heart catheterization and intervention. Indian Heart J. 2010;62(3):245-250.

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From the Deborah Heart and Lung Center, Browns Mills, New Jersey.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted February 11, 2013, provisional acceptance given March 20, 2013, final version accepted October 18, 2013.

Address for correspondence: Kintur Sanghvi, MD, FACC, FSCAI, Director of Transradial program, Clinical Associate Professor, Deborah Heart and Lung Center, 200 Trenton Road, Browns Mills, NJ 08015. Email: lpgroben@gmail.com