The importance of bifurcation lesions in patients undergoing percutaneous coronary interventions in ST-segment elevation myocardial infarction.

BACKGROUND: Bifurcation lesions at the time of emergent PCI for STEMI are relatively common. However, there are little data regarding their significance. The objective of this study is to evaluate the impact of bifurcation lesions in the setting of emergent percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). METHODS: In 391 patients who underwent primary and rescue PCI, the clinical characteristics, procedural success, and in-hospital cardiac events were compared retrospectively between the patients with and without bifurcation lesions. The PCI strategy was at the discretion of the operator. RESULTS: The culprit artery involved a bifurcation lesion in 54/391 (14%) patients. The baseline clinical characteristics between the groups with and without bifurcation lesions were similar. The majority of bifurcation lesions (81%) were seen in the left anterior ascending (LAD) artery. All lesions were treated with the provisional stenting approach, and only 2 (3%) patients required 2 stents. There were no difference in the procedural success and the final TIMI-3 flow, but PCI of bifurcation lesion required higher amount of contrast use. There was no in-hospital MACE in the bifurcation group. The peak cardiac enzyme, left ventricular function, and length of stay were similar in these 2 groups. CONCLUSIONS: Bifurcation lesions are relatively common in emergent PCI for STEMI involving the LAD. It can be safely treated with a provisional stenting approach, and the immediate outcome is similar to non-bifurcation lesions.

Meta-analysis of prospective randomized controlled trials comparing intracoronary versus intravenous abciximab in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Abciximab is a glycoprotein IIb/IIIa receptor inhibitor that has been shown to improve outcomes in patients with ST-segment elevation myocardial infarction who undergo primary percutaneous coronary intervention (pPCI). An earlier study reported better efficacy with intracoronary (IC) compared to intravenous (IV) administration, but this finding has not been duplicated in other studies, thus leaving a great deal of uncertainty as to the most efficacious route of administration. To investigate if IC abciximab compared to IV administration decreases mortality and major adverse cardiac events in patients with ST-segment elevation myocardial infarction who undergo pPCI, a meta-analysis was performed consisting only of prospective randomized controlled trials. Subgroup analysis was performed to investigate the source of difference in efficacy between the 2 strategies. A meta-analysis of 4 trials including 1,148 subjects revealed that IC abciximab significantly reduced mortality compared to IV administration (1.5% vs 3.6%, odds ratio 0.44, 95% confidence interval 0.20 to 0.95, p = 0.04). Major adverse cardiac events were also reduced in a subgroup in which <30% of patients received aspiration thrombectomy (6.1% vs 16.2%, odds ratio 0.33, 95% confidence interval 0.18 to 0.61, p = 0.0004). In conclusion, the totality of the data available from relatively small but high-quality studies shows a significant mortality reduction associated using IC abciximab for pPCI compared to IV abciximab. IC abciximab in the setting of pPCI for ST-segment elevation myocardial infarction may be beneficial for patients with higher risk profiles.

Transradial cardiac catheterization: a review of access site complications.

Transradial catheterization (TRC) has been associated with a lower incidence of major access site related complications as compared to the transfemoral approach. With the increased adoption of transradial access, it is essential to understand the potential major and minor complications of TRC. The most common complication is asymptomatic radial artery occlusion, which rarely leads to clinical events, owing to the dual collateral perfusion of the hand. Adequate anticoagulation, appropriate compression techniques, and smaller sheath size can minimize the risk of radial artery occlusion. Hand ischemia with necrosis has never been reported during TRC with thorough pre-examination of intact collateral circulation. Radial artery spasm is relatively common, and can result in access and procedural failure. It can be prevented by the use of vasodilator cocktails and hydrophilic sheaths. Radial artery perforation can lead to severe forearm hematoma and compartment syndrome if not managed promptly. Careful observation, prompt detection of the hematoma, and management with a pressure bandage dressing are critical to avoid serious complications. Pseudoaneurym and arteriovenous fistula are rare complications, which can likely be managed conservatively without surgical intervention. Nerve injury occurring during access has been reported. Close observation for improvement is necessary, although symptoms usually improve over time. In summary, to prevent access site complications, avoidance of multiple punctures, gentle catheter manipulation, use of guided compression, coupled with careful observation for adverse warning signs such as hematoma, loss of pulse, pain, are critical for safe and effective TRC.

Randomized comparison of transradial coronary angiography via right or left radial artery approaches.

Previous studies have shown that the right radial approach encounters more tortuosity than the left radial approach during transradial coronary angiography. The objective of this study was to compare the procedural difficulty of the right and left radial approaches in the modern era with dedicated transradial catheters. One hundred ninety-three patients scheduled for transradial coronary angiography with normal Allen test results and without histories of coronary artery bypass grafting were randomized to the right or left radial approach. The choice of catheter was left to the discretion of the operator, with the preferred catheter being a dedicated transradial Optitorque catheter. The primary end point was procedural difficulty, defined as (1) hydrophilic or coronary wire use for tortuosity, (2) stiff wire use for the coronary engagement, (3) multiple catheters used, or (4) nonselective injection. The clinical characteristics were similar between the 2 groups. Procedural success was achieved in 98 of 101 (98%) in the right radial group and 91 of 92 (99%) in the left radial group. Procedural difficulty, fluoroscopy time, and contrast use were similar between the 2 groups. The use of a single catheter was more common in the right radial group (73% vs 18%, p <0.001). In conclusion, procedural success and difficulty were similar in the comparison groups. The right and left radial approaches are feasible and effective to perform coronary angiography and intervention.

Long-term outcome of bifurcation stenting with drug-eluting stents.

There are little long-term clinical data regarding the safety and efficacy of using 2 drug-eluting stents (DESs) to treat coronary bifurcation lesions. We obtained clinical follow-up for 124 consecutive patients who underwent bifurcation stenting with 2 DESs. Major adverse cardiac events (MACEs) were defined as cardiac death, acute myocardial infarction (AMI), and target vessel revascularization (TVR). Sixty-four (52%) patients underwent ''crush,'' 42 (34%) patients underwent T stent, and 18 (14%) patients underwent kissing stent. Major adverse cardiac events were observed in 19 patients (17%) at 1 year: 6 (5%) AMI, 13 (12%) TVR, and no deaths, and 29 patients (26 %) at a mean follow-up of 22 months: 7 (6%) AMI, 21 (19%) TVR, and 1 (1%) death. No statistically significant risk factors for long-term MACEs were identified. It appears that treating bifurcation lesions with 2 DESs when necessary can be performed with an acceptable MACE rate.

Relation of race (Asian, African-American, European-American, and Hispanic) to activated clotting time after weight-adjusted bolus of heparin during percutaneous coronary intervention.

A weight-adjusted bolus of heparin (70 to 100 IU/kg) is recommended to achieve adequate anticoagulation during percutaneous coronary intervention (PCI). Proper dosing is mandatory to avoid bleeding and thrombotic complications. We investigated whether sensitivity to heparin is affected by difference in race. We performed a retrospective study with 874 consecutive PCI cases in our catheterization laboratory. The amount of initial heparin bolus (international units) per weight and subsequent activated clotting time (ACT; seconds) were obtained. Patients were divided into 4 categories based on race: Asian, African-American, European-American, and Hispanic. Multiple regression analysis was performed to validate the variables that determine the ACT. After adjusting for these variables, analysis of variance revealed the presence of a significant racial difference in ACT (p = 0.002). Successively, Student-Newman-Keuls test and Bonferroni t test revealed that Asian patients have higher ACT levels compared to other racial groups (p <0.03 for Asian vs others, p >0.26 between non-Asian groups). There was a positive relation between ACT and Asian race (p = 0.0004). Further analyses showed that Asians require 10 IU/kg less heparin per weight than other racial groups to achieve the same goal of ACT. In conclusion, decreased heparin dosing should be considered for Asian patients undergoing PCI.

Frequency of severe renal artery stenosis in patients with severe thoracic aortic plaque.

Atherosclerotic renal artery stenosis (RAS) is an underdiagnosed disorder and a treatable etiology of hypertension and renal insufficiency. All patients were referred for a transesophageal echocardiogram for various indications. Abdominal ultrasound was performed in 69 patients, 43 with severe thoracic aortic plaque (> or =4 mm) and 26 controls with no or mild plaque (< or =2 mm). Severe RAS (> or =60%) was defined as flow velocity > or =1.8 m/s and a renal:aortic ratio of > or =3.5. There were 8 cases of RAS (all severe) in the 43 patients with severe aortic plaque (19% vs 0% of controls; p = 0.02). Severe plaque (p = 0.02) and hypertension (p = 0.03) were correlated with RAS. On multivariate analysis, severe plaque (p = 0.017) and hypertension (p = 0.002) remained independently correlated with RAS. In a paired analysis, matched for age and gender (McNemar), severe plaque was significantly associated with RAS (p = 0.008). Severe thoracic aortic plaque is strongly associated with RAS, which is found in 19% of patients with severe plaque. Patients found to have severe aortic plaque on transesophageal echocardiography should be screened for RAS.