Feasibility and Safety of Elective Transradial Coronary Intervention in Asian Females

ABSTRACT: Background. Transradial access for angioplasty and percutaneous intervention (PCI) has become more popular across the world due to lower risk of bleeding and better patient comfort. It has been shown to be effective and feasible in the Western population. However, there is a relative paucity of similar data for small-statured females, especially from Asian countries. Given the increased theoretical risk of local complications due to smaller-sized radial arteries in such females, feasibility and safety of transradial PCI (rPCI) needs to be better established in this group. Methods. We present observational data for rPCI from a 3-year period at a single tertiary care center in South Asia. Data were collected on all female patients who underwent rPCI from January 2005 to December 2007. Primary outcomes assessed were procedure failure rate and complication rate. Secondary outcomes included death, recurrence of myocardial infarction, anginal symptoms or other complaints. Outcomes were recorded post-procedurally in the hospital and after discharge for up to 6 months. Results. A total of 93 patients were included for final data analysis. Average patient age was 57.5 ± 10.3 years, with average height of 151.7 ± 8.4 cm and average weight of 58.1 ± 12.5 kg. Seventy patients (75.3%) underwent angioplasty or percutaneous intervention (PCI) for ACS and 23 (24.7%) for chronic stable angina refractory to medical therapy. A total of 118 lesions were treated in 90 patients. Ninety-one lesions (77.1%) were classified as Type B2 and Type C according to modified American College of Cardiology/American Heart Association lesion morphology criteria. Three cases of procedure failure accounted for a failure rate of 3.23%. No specified complications were noted in any of the patients. At 6-month follow-up, no deaths were observed. Two patients developed acute myocardial infarction and 16 patients (17.7%) had recurrence of anginal symptoms. Conclusion. Radial artery angioplasty and stenting is feasible and safe in Asian females. Increased theoretical risk of complication due to small-sized radial arteries in this subgroup is unlikely to be true. Success rates are likely to be good even with complex coronary inventions performed with transradial access. J INVASIVE CARDIOL 2011;23:95–98 ————————————————————

Transradial percutaneous coronary intervention (rPCI) is associated with fewer vascular access-site complications without any increased major adverse cardiovascular events (MACE) when compared to transfemoral percutaneous coronary intervention (fPCI) in a standard western population.^1,2 Transradial vascular access has been shown to be effective and feasible even in the setting of primary PCI³ and with the use of high-speed rotational atherectomy.⁴ With the increasing use of glycoprotein IIb/IIIa inhibitors, anticoagulants and high-dose antiplatelet therapy with PCI, minimizing the chance of access-site bleeding has become imperative to reduce the length of hospital stay and need for blood transfusion. All this would imply an increased use of rPCI in the future. The majority of rPCI studies were done in Western populations. There is a relative paucity of data specifically addressing the feasibility and safety of rPCI in Asian females. Radial arteries, which are smaller than femoral arteries, are more likely to have higher rates of asymptomatic loss of pulse² as well as higher rates of access failure.^1,2 Asian females are typically small-statured and are more likely to have small radial arteries that may be more prone to periprocedural arterial spasm, a higher complication rate and procedure failure. We present single-center data on the feasibility and safety of rPCI in Asian females.

Methods

The study was designed as a retrospective single-center study. Formal approval for data collection was obtained from the IRB of the institution. We collected the data of elective rPCI done by a single operator at a single tertiary center from January 2005 to December 2007. Elective PCI was defined as any PCI done as early invasive strategy for acute coronary syndrome or for failed medical therapy in cases of chronic stable angina. Patients undergoing primary PCI and left main coronary artery (LMCA) stenting were excluded. All patients were followed for at least 6 months. Information was collected regarding procedural and post-procedural complications, including both in-hospital and post-discharge complications. Primary outcomes assessed included procedure success rate and complication rate. Complications analyzed included dissection of the radial artery, signs and symptoms of ischemia to the hand, coronary complications, bleeding involving access site and other sites, including retroperitoneal, intracranial, gastrointestinal and genitourinary bleeding. Death, recurrence of myocardial infarction, anginal symptoms or other complaints was recorded post-procedurally in the hospital and after discharge on follow-up visits at 2 weeks, 3 months and 6 months.

The procedure was preceded by Allen’s test to confirm the presence of collateral circulation. Right radial artery puncture was done using the 6 French (Fr) Cordis transradial kit (Cordis Corporation, Miami Lakes, Florida). Immediately after sheath insertion, a cocktail containing 200 micrograms of nitroglycerin, 40 mg of 1% lidocaine and 5,000 units of heparin was given intra-arterially through the sheath. Bivalirudin (0.75 mg/kg intravenous pre-PCI, 1.75 mg/kg/hour during PCI), eptifibatide (180 microgram/kg bolus followed by a continuous infusion of 2.0 microgram/kg/minute for 12 hours) or unfractionated heparin (100 units/kg body weight) was used for anticoagulation or anti-platelet therapy. Heparin was not added to the cocktail when bivalirudin was planned periprocedurally. Judkin’s left 3.5 curve or EBU 3.5 guide catheters were used for left coronary artery cannulation and Judkins right 3.5 curve guide catheter for right coronary artery cannulation. 0.032-inch peripheral wire was used to negotiate entry into the aorta. When there was a problem while entering the aorta, a Terumo 0.032-inch wire was used. Export catheters (Medtronic, Minneapolis, Minnesota) compatible with 6 Fr guides were used for thrombus aspiration when needed. For bifurcation lesions, provisional stenting of the main vessel followed by kissing-balloon dilatation of the main and sidebranch was performed. For sidebranch lesions, after stenting the main vessel, stenting of the sidebranch was done with an inflated balloon in the main vessel. No other interventional devices were used. The radial sheath was removed immediately after PCI and a soft bandage was applied for 6 hours. Patients were discharged the next day; at the time of discharge, patents were continued on 3 antiplatelet drugs (aspirin 150 mg, clopidogrel 75 mg and cilostazol 100 mg) along with beta-blockers. Angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers were prescribed when appropriate. Radial pulse and access site were examined post-procedurally, prior to discharge and at outpatient follow-up. At first follow-up at 15 days, radial pulse was examined and all complaints were recorded, including symptoms of ischemia to the hand. Patients were followed for at least 6 months.

Statistical methods. Continuous variables are reported as means ± standard deviations (SD). Categorical variables are presented as percentages. Complication rates are presented in absolute numbers and/or percentages. Procedural failure was defined as inability to perform the planned angioplasty due to failure to access the intended radial artery, failure to cannulate the coronary arteries, failure to cross the lesion with wire or failure in deployment of stent or balloon. Procedure success rate was defined as (1 - % procedure failure rate) times 100.

Results

A total of 473 PCI were performed during the study period. A total of 90 females who underwent elective PCI were included in the study. Average patient age was 57.5 ± 10.3 years, average height was 151.7 ± 8.4 cm, and average weight was 58.1 ± 12.5 kg (Table 1). The average weight was thus under the 25th percentile of weight trends in American females.⁵ Hypertension was present in 67 patients (74.4%) and diabetes in 39 patients (43.3%) (Table 2). The vast majority of patients (75.3%) underwent PCI for ACS as early invasive strategy. Out of these, 36 (38.7%) had acute non-ST elevation myocardial infarction and 34 (36.5%) had unstable angina. Twenty-three patients (24.7%) underwent PCI for chronic stable angina refractory to medical therapy. A total of 118 lesions treated were in 90 patients. This included multiple complex lesions, such as lesions with calcium, ostial lesions, thrombus-containing lesions, ulcerated lesions and bifurcation lesions, and total occlusions (Table 3). The left anterior descending artery was the most common location of targeted lesions (46.6%). For lesions with thrombus (n = 20), export thrombus aspiration was done before stenting the lesion. Ninety-one lesions (77.1%) were classified as Type B2 and Type C according to modified American College of Cardiology/American Heart Association lesion morphology criteria. Thirty patients received eptifibatide with unfractionated heparin, 12 received bivalirudin alone and 3 received a combination of eptifibatide and bivalirudin for anticoagulation and antiplatelet therapy. Forty-five patients received only unfractionated heparin. None of the patients intended for transradial access had abnormal Allen’s tests. Failure to cannulate the radial artery was encountered in 1 case and prolonged arterial spasm was noted in another case with arteria lusoria. Both cases required conversion to the transfemoral approach. One chronic total occlusion lesion could not be crossed. These 3 cases of procedural failure accounted for a failure rate of 3.23%. Overall procedure success rate was 96.7%. Radial loops and subclavian angulations could be overcome by gentle manipulation of the Terumo catheter and did not require switching to the transfemoral approach. Significant culprit vessel tortuosity and angulations was present in 7 patients (7.8%) and did not affect the procedure. Coronary anomalies were found in 2 patients who had right coronary artery origin from the left sinus and were engaged with left Amplatz 1 guides. Average reference coronary vessel diameter was 2.52 ± 0.56 mm, reflecting the relatively smaller size of coronary arteries in Asian females. Average lesion length was 12.4 ± 7.7 mm. With PCI, significant improvement was noted in minimum luminal diameter and percent stenosis (Table 4). One patient had no reflow after stent deployment that was improved after balloon inflation to TIMI 2 flow. None of the patients required a referral for urgent coronary bypass surgery. There was transient asymptomatic loss of palpable radial pulse in 3 patients (3.3%) after sheath removal. Doppler examination was normal in all 3 patients, suggesting radial artery spasm. No puncture site complications were noted and no clinically significant hematomas were found in any patient. At 6-month follow-up, no deaths were observed. Two patients developed acute myocardial infarction and 16 patients (17.7%) had recurrence of anginal symptoms. All 18 patients underwent successful repeat culprit lesion revascularization with rPCI.

Discussion

Transradial access for angioplasty has been gaining momentum since Kiemeneij and Laarman first used it in 1993.⁶ Despite fairly rapid dissemination of the technique, rPCI is used infrequently compared to fPCI.⁷ Compared to transfemoral access, the transradial approach has been shown to be safe,² associated with fewer bleeding and local access site complications. Furthermore, a trend toward better cardiovascular outcomes^1,7,8 due to reduced morbidity, shorter hospital stays and better cost-effectiveness has been demonstrated with rPCI.⁹ However, these benefits are offset by increased radiation exposure due to prolonged fluoroscopy times and increased rates of unsuccessful catheterization. A steeper learning curve is associated with the rPCI.¹⁰ Relative lack of familiarity and reluctance in adopting a more recent approach on the part of the interventional community are potential reasons for less frequent use of rPCI compared to fPCI. As a consequence, there is a relative paucity of data on the safety and feasibility of the transradial approach for angioplasty in specific subgroups of patients, such as females, non-Western populations, and those with low body mass index (BMI) or short stature. This study addresses the safety and feasibility of rPCI in one such group represented by Asian women. The largest group of data on rPCI in females is available from the United States NCDR registry.⁷ Approximately 30% of the 7,804 rPCI cases in this large database were performed on female patients. The procedural success rates were not statistically different between males and females. However, bleeding complications were noted to be lower in females. Of note, the patients in this database had a higher mean BMI of 29.71 kg/m² (combined males and females) compared to our study population with a mean BMI of 25.2 kg/m². Hence, it would be difficult to extrapolate these data to rPCI in Asian females. Tse et al demonstrated good procedural success of elective rPCI in 118 Chinese patients in their study group, of which 25% were females.¹¹ In a small series of female patients from India, Ranjan et al reported successful use of rPCI in the setting of acute MI.¹² Our study is the largest to describe the results of rPCI in south Asian females. Women tend to have smaller radial arteries compared to men. According to Chi-Hung Huang et al, the mean radial artery inner diameter (RAID) in males was larger compared to females (2.88 ± 0.39 versus 2.53 ± 0.32 mm; p 13 Body habitus also influences radial artery size. Compared to Western populations, the caliber of the radial artery in Asians is smaller. The mean radial artery diameter has been reported to be 3.67 ± 0.8 mm in a Western population,¹⁴ compared to 2.63 ± 0.35 mm in an Asian population,¹⁵ which typically has a smaller body habitus. These anatomical differences theoretically increase the risk of radial artery spasm, occlusion or other vascular complication rates as well as the chance of procedural failure in Asian females. We, however, did not notice any difference in procedure success rate (96.7%) compared to data from a Western population (95.5%), putting such concerns to rest.⁷ In addition, the combined bleeding and vascular complication rates in our study (0%) compared well with the data from western databases (7<.sup> In a study by Gwon et al, procedural success and local complication rates were similar with the use of 5 Fr catheter for radial PCI compared to use of a 6 Fr catheter.¹⁶ Theoretically, radial artery spasm may be more frequent with a larger sheath. However, in our study, the routine use of 6 Fr sheaths for cannulation did not seem to adversely affect the local complication rate. Radial artery spasm was seen in only 1 out of 92 patients and no cases of occlusion or dissection of radial artery were observed. The use of 6 Fr catheters is often preferred over smaller catheters while dealing with complex lesions, especially when using distal protection, thrombectomy or atherectomy devices, and when the stent size is > 3 mm. We did not encounter any problem in thrombus aspiration and management of bifurcation lesions with the use of 6 Fr sheaths. For bifurcation lesions, we used the crush-stent technique suggested by Lom and Dzavik.¹⁷ This technique involves initially placing a stent in the sidebranch and a balloon in the main vessel; the sidebranch stent is then deployed against the main vessel balloon that is later inflated, crushing the sidebranch stent within the main vessel. The main vessel is then stented and the sidebranch re-crossed for kissing inflations. The kissing balloon technique could be successfully performed in our study for bifurcation lesions (n = 18). Study limitations. The biggest limitation of the study is that it comprises a single-center, single-operator data pool, which restricts the generalization of these results. As with any other intervention, the experience of the operator would affect the outcome. The results from this study suggest that in experienced hands, small stature and female gender should not be prohibitive to a radial approach for PCI. Notably, the results from this study in no way conclusively compare radial to femoral approaches. This has been addressed in randomized trials in Western populations, but similar studies in Asian females have not been performed and may give more insight into this patient subgroup. Our study does reinforce the safety and feasibility of rPCI in such subgroups. Another potential drawback of this study is the lack of patients undergoing primary rPCI for acute ST-elevation myocardial infarction. Hence, our observations may not be applicable to this patient subset. There was, however, a good representation of patients undergoing PCI for early invasive strategy with acute coronary syndrome, as well as those undergoing PCI for chronic stable angina. The study lacks information on the procedure time and time under fluoroscopy, as they were not routinely recorded. Despite these limitations, we believe that this study supports use of the transradial approach for angioplasty in Asian females, who are typically short-statured and have low BMI. It is important to note the high success rate of rPCI despite the presence of a significant number of patients with complex lesions, such as chronic total occlusions, ostial and bifurcation lesions (Table 3) in this study.

Conclusion

Elective transradial angioplasty is safe and feasible in Asian females. Short stature and smaller radial artery diameter are unlikely to impact procedural success or complication rates.

References

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———————————————————— From ^*Creighton University Medical Center, Omaha, Nebraska, and ^§Nizam’s Institute of Medical Sciences, Hyderabad, India. The authors report no conflicts of interest regarding the content herein. Manuscript submitted August 4, 2010, provisional acceptance given September 13, 2010, final version accepted November 2, 2010. Address for correspondence: Manu Kaushik, MD, Creighton University Medical Center, Division of Cardiology, 3006 Webster Street, Omaha, NE 68131. E-mail: drmanukaushik@gmail.com