Safety and feasibility of emergent percutaneous coronary intervention with the transradial access in patients with acute myocardial infarction

The use of intense anticoagulation and antiplatelet therapy in acute myocardial infarction (AMI) potentially increases the risk of bleeding complications during percutaneous coronary intervention (PCI) via the transfemoral approach. Recently, the transradial access has been increasingly employed as an alternative means for diagnostic and interventional procedures. Low incidence of vascular access site bleeding complications suggests the transradial approach as a safe alternative to the femoral technique in AMI, particularly under an aggressive anticoagulation/antiplatelet regimen.1,2 Nevertheless, the safety and feasibility of employing the transradial approach for primary PCI in AMI has not been thoroughly investigated so far. METHODS Study population From June 2004 to June 2006, 370 consecutive patients were admitted to our hospital diagnosed as AMI within 12 hours from the onset of chest pain. Exclusion criteria for the transradial approach were a negative Allen test, aorto-arteritis, cardiogenic shock, non-palpable radial artery, severe tortuosity of radial arteries or body height 0.05). Crossover from the radial to femoral access was required in 3 patients, and from the femoral to radial access required in 2 patients. There were no dramatic differences in the cannulation and total procedure time (P>0.05). No significant differences were observed in recanalization with TIMI III flow of culprit vessels (P>0.05).Table 3: Procedural and angiographic characteristicsGuiding catheter selection Compared with the TFI group, Judkins left (JL) guiding catheters were used less (22(20.0%) vs 66(60.5%), P< 0.01) and long-tip guiding catheters (EBU, XB, Q curve and Voda) were selected more often (EBU: 40(36.4%) vs 18(16.5%), P<0.01; XB: 17(15.5%) vs 7(6.2%), P<0.05; Q curve and Voda: 22(20.0%) vs 16(14.3%), P<0.05) for the left coronary artery (LCA) in the TRI group. In approaching the RCA, the XBRCA guiding catheters were more frequently employed (39(52.7%) vs 18(23.4%), P<0.01) and Judkins right guiding catheters were selected less (16(21.6%) vs 45(58.4%), P<0.01) in the TRI group compared with the TFI group. Complications Compared with the TFI group, vascular access site and post-procedure complications occurred less in the TRI group (local hematoma: 7 vs 2, P<0.05; vagus reflex: 15 vs 0, P<0.01; difficult micturating: 13 vs 0, P<0.01; low back pain: 8 vs 0, P<0.05). In the TRI group, severe radial spasm was found in 3 patients, which were relieved after nitroglycerin deliveration. DISCUSSION Transfemoral approach is a conventional method for PCI, but apt to cause vascular access site complications. Even with weight-adjusted heparin dosing and small-caliber guiding catheters, significant vascular access site complications occurred in almost 10% of patients in a recent series of transfemoral PCIs.3 Recently, several studies have shown that the transradial access is an attractive option for approaching the vessel in coronary angiography and interventions due to lower access site complications, a shorter hospital stay, and increased patient comfort.4-6 Saito et al4 found that the success rate of reperfusion and incidence of major adverse cardiac events (MACE) during the initial hospitalization and 9-month follow-up periods were similar in these two approaches. Consistent with Kim et al,1 the present study illustrated that there were no significant differences in the cannulation time, total procedure time, successful rates of puncture and TIMI flow of culprit vessels between the transradial and transfemoral approaches in patients with AMI. Therefore, for most of the hemodynamically stable AMI patients, the transradial approach is a good option which may take the place of the transfemoral access. Louvard et al6 found that the incidence of severe bleedings in the transradial approach were dramatically lower than via the transfemoral approach. The results of our study demonstrated that the transradial approach showed a dramatically lower incidence of vascular access site complications compared with the transfemoral approach. The safety of the transradial approach is mainly determined by the anatomic relations of the radial artery to its surrounding structures: radial artery goes through forearm lateral lonely, without important concomitant veins and nerves. Crossover from radial to femoral access was required in 2 patients, because of severe radial tortuosity and spasm. If spasm occurs, delivery of nitroglycerin and/or verapamil through the sheath can be helpful.7 In general, guiding catheter support provided by the transradial approach is markedly reduced compared with the transfemoral approach. It has been reported that the backup force was 60% greater in TFI with a JL catheter, but with a backup (EBU/XB) type catheter, only 8% greater in TFI than that in TRI. In our study, good backup support for the transradial approach has been achieved by using the guiding catheters with special curve, such as EBU, XB, Q curve, Voda and XBRCA guiding catheters. Therefore, it showed no statistical differences in the successful rates in emergent PCI with the transradial approaches compared with the transfemoral approaches. Compared with the transfemoral approach, transradial procedures are technically more challenging because of: (1) greater difficulty in cannulating the relatively small radial artery; (2) variations in radial anatomy; (3) the occurrence of spasm. A fairly steep learning curve exists to switch to the transradial approach.Thus, emergent PCI in AMI with the transradial approach should be completed only by the experienced interventional experts who have gone beyond the learning curve. In conclusion, provided by the experienced operators, the transradial approach may represent a safe and feasible technique for AMI with similar results and a trend toward less bleeding complications as compared with the transfemoral approach.