Transradial (TR) cardiac catheterization is underused, possibly because of perceived technical difficulty and longer procedure times. We compared TR to transfemoral (TF) coronary angiography as performed by experienced TF angiographers with varying TR skills. Data were analyzed for diagnostic angiography without ad hoc intervention over a 12-month period comparing TR to TF procedural and fluoroscopic times, contrast volume, and complication rates. Further analysis was performed according to operators’ TR experience (radial expert [REx] vs non-radial expert [nREx]). In total 1,001 patients were identified (661 TR and 340 TF cases) with nRExs performing an average of 63 TR procedures each. All TF procedures were successful and 92% were successful for TR angiography; complication rates were similar regardless of access. Compared to TF procedures fluoroscopic times were longer in the all-operator TR group (5.3 vs 4.0 minutes, p <0.01) but total procedural times were not (TR vs TF 24 vs 22 minutes, p = NS). In the TR group nRExs had longer fluoroscopic and procedural times compared to RExs in the first 3 months of radial experience (8 vs 4.4 minutes, p = 0.02, and 32 vs 22 minutes, p <0.01, respectively); however, the 2 were equivalent in the final 3 months of analysis (5.2 vs 4.5 and 26 vs 19 minutes for nRExs and RExs, respectively, p = NS). Within the nREX group parameters improved in the last compared to the first 6 months (fluoroscopy 6 vs 7.3 minutes, p = 0.04; procedure time 26 vs 30 minutes, p = 0.04). In conclusion, TR coronary procedures appear to be a comparable alternative to TF procedures with a relatively short technical learning curve.
Transradial (TR) coronary angiography is less widely used than the transfemoral (TF) approach despite proven feasibility and greater safety. We compared procedural parameters when using these 2 vascular access techniques for coronary angiography as performed by experienced TF angiographers who had varying radial access skills. We also assessed the learning curve of operators new to TR angiography.
Methods
We performed a systematic retrospective review of patients who underwent diagnostic coronary procedures at North Shore Hospital, Auckland, New Zealand in the 12 months from January through December 2008. That period covered the early learning stage for most non-interventional angiographers in our institute; our current TR rate is >85% for diagnostic and percutaneous coronary intervention (PCI) procedures. Thus procedures were performed by a mix of “radial experts” (RExs; 3 operators in this analysis) and others with basic or early TR skills (“non-experts” [nRExs]; 5 operators); all were competent TF angiographers. Choice of access was at the operator’s discretion. Only patients with complete data and who had diagnostic angiography without intervention were included. Patients with previous coronary artery bypass grafting surgery were excluded.
For TR catheterization a satisfactory Allen test result was ascertained and those with contraindications (current or planned hemodialysis shunts, single remaining radial artery or local infection) were excluded. After subcutaneous local anesthesia the radial artery was cannulated with a 5Fr or 6Fr Radifocus introducer sheath (Terumo, Tokyo, Japan). Patients received intra-arterial unfractionated heparin 5,000 U and intra-arterial verapamil 2.5-mg bolus; further intra-arterial verapamil or glyceryl trinitrate was discretionary. Femoral arteries were cannulated similarly with 5Fr or 6Fr sheaths. Optional unfractionated heparin 2,000 U was administered. Catheterization was performed in the standard manner using 4Fr, 5Fr, or 6Fr catheters for TR and 5Fr or 6Fr catheters for TF approaches. An automated contrast injector (ACIST™; ACIST Medical Systems, Eden Prairie, Minnesota) was used in all cases. Injector volume parameters and angiographic views were at the operator’s discretion; approximately 10 ml of contrast was used for the left and 8 ml for the right coronary systems to obtain an average of 10 cine runs; left ventriculography was optional. Vascular sheaths were removed at the conclusion of the procedure for the 2 access routes. Radial hemostasis was obtained using a TR-Band (Terumo, Tokyo, Japan), a Velcro-secured wrist band with an inflatable compression bladder, according to our standard wean protocol described previously, and femoral hemostasis was obtained mostly by digital pressure or FemoStop (Radi Medical Systems, Reading, Massachusetts) application in the usual manner.
An experienced femoral angiographer who received formal training in radial techniques with >100 previous TR procedures was considered an REx. At our institution diagnostic angiography is performed by invasive cardiologists and fellows who, at least in the early phase of analysis, had basic or no radial experience. Interventionists, who are RExs as defined earlier, perform diagnostic angiography with or without ad hoc PCI. Procedural success was defined as completion of the procedure through the primary access; failed radial procedures completed through a secondary femoral puncture were analyzed with the radial group. Access-site complications assessed were radial or femoral dissections (with/without vascular repair) or significant radial/femoral hematoma (>5-cm diameter, bleeding >3 g/L, or requiring blood transfusion). Other complications were contrast reactions, cerebrovascular events, coronary dissections, myocardial infarction, and death.
Outcomes measured were procedural time (in minutes) from local anesthetic infiltration to procedure completion (regardless of success/failure or need for secondary vascular access), fluoroscopic time (in minutes), and radiocontrast volume (in milliliters) used during the procedure. There was a considerable spread of procedure times among operators, so median values were used to compensate for outliers. Outcomes were analyzed by access site. TR outcomes were further compared by REx and nREx status and by quartiles within the 12-month analysis period. Gender comparison of TR outcomes was also performed because a smaller radial artery caliber may, at least in theory, render the procedure more difficult in women.
Continuous variables are presented as medians and categorical variables as counts and percentages. Outcome comparisons were done using Fisher’s exact test and unpaired Student’s t test for categorical and continuous variables, respectively. Statistical analysis was performed using SAS 9.1 (SAS Institute, Cary, North Carolina). Differences between groups were statistically significant at a p value <0.05.
Results
In total 1,001 patients (661 TR and 340 TF cases) were identified. Table 1 lists patient characteristics and procedural indications. There were no significant biometric differences between TR and TF cases or men and women regardless of ethnicity.
| Men | 634 (63%) |
| Ethnicity ⁎ | |
| European | 759 (76%) |
| Maori | 56 (6%) |
| Pacific Islander | 56 (6%) |
| Asian | 70 (7%) |
| Middle Eastern/Latin American/African | 9 (1%) |
| Other/nonspecified | 51 (5%) |
| Age (years) | 64 ± 12 |
| Weight (kilograms) | |
| Women | 72 ± 19 |
| Men | 85 ± 16 |
| Height (cm) | |
| Women | 160 ± 7 |
| Men | 174 ± 8 |
| Body mass index (kg/m 2 ) | |
| Women | 28 ± 7 |
| Men | 28 ± 5 |
| Indications for procedure | |
| Definite or suspected coronary ischemia | 853 (85%) |
| Valvular heart disease | 71 (7%) |
| Heart failure syndromes | 36 (4%) |
| Arrhythmia | 14 (1%) |
| Other/nonspecified | 27 (3%) |
RExs performed 343 TR and 101 TF procedures compared to nRExs who performed 318 TR and 239 TF procedures. Procedural outcomes comparing the 2 access techniques are presented in Table 2 . TR procedures were unsuccessful in 8%, whereas all TF procedures were successful. Causes for TR failure were inability to puncture the radial artery, severe spasm, or significant tortuosity. Including the early learning period for nRExs, fluoroscopic and procedural times were longer for TR versus TF procedures in this group. For RExs and nREXs combined, procedure times were similar for TR and TF approaches (24 vs 22 minutes, p = NS) but TR procedures had longer fluoroscopic times (5.3 vs 4.1 minutes, p <0.01). There were no differences in vascular complications within groups (2 radial artery dissections, 0.3%; 1 femoral artery dissection, 0.3%); another 4 patients (0.6%) in the TR group had minor contrast reactions.
| Variable | TF Access | TR Access | p Value |
|---|---|---|---|
| (n = 340) | (n = 661) | ||
| Total procedure duration (minutes) | |||
| Radial experts | 24 | 20.5 | NS |
| Non-radial experts | 22 | 27 | <0.001 |
| Total fluoroscopic time (minutes) | |||
| Radial experts | 4.4 | 4.5 | NS |
| Non-radial experts | 3.6 | 6.2 | <0.001 |
| Total contrast volume (ml) | |||
| Radial experts | 120 | 108 | <0.001 |
| Non-radial experts | 140 | 119 | <0.001 |
Compared to men (n = 217) having TF procedures women (n = 123) had a shorter total procedural time (20 vs 26 minutes), a shorter fluoroscopic time (3.2 vs 4.5 minutes), and had less contrast use (124 vs 146 ml, p <0.001). TR procedures showed no gender differences in time parameters (24-minute procedure time for men and women and fluoroscopy times of 5.2 vs 5.5 minutes, p = NS); however, less contrast was used in women (100 vs 119 ml, p <0.001). Left ventriculography was performed in 485 patients (48%) and more commonly in men (54%) than in women (39%) but with no statistically significant effect on contrast volume. There were no differences in complication rates by gender and TR failure rates were the same for women and men (6.6% and 8.4%, respectively, p = NS).
Table 3 lists procedural characteristics compared by TR expertise. During the 12 months analyzed failure rates were similar between the REx and nREx groups (9, 5.3%, and 42, 8.6%, respectively, p = NS). nRExs overall had longer procedure times (27 vs 24 minutes, p <0.001) and longer fluoroscopic times (6.2 vs 5.3 minutes, p <0.004) than RExs. Contrast volumes were similar (111 vs 119 ml, p = NS). However, even with modest procedural numbers (approximately 36 procedures/operator in first 9 months, 63 procedures by 12 months), technical differences decreased rapidly as nRExs gained more experience. Differences between nRExs and RExs in the first 3 months of analysis were no longer apparent in the last 3 months. More specifically, within the nREx group there was a significant rapid improvement trend in procedural parameters over the study period ( Figure 1 , Table 4 ), with the last 6 months showing shorter procedural times compared to the first 6 months (82 vs 236 procedures in first vs last 6 months).
