Morbidly Obese Patients Fare Better with Transradial Technique

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In patients with morbid obesity who are referred for angiography or percutaneous coronary intervention (PCI), the transradial approach is less likely to lead to bleeding and access site complications than the transfemoral route, according to a study published online August 20, 2012, ahead of print in JACC: Cardiovascular Interventions. 

Edward R. O’Brien, MD, of the University of Ottawa (Ontario, Canada), and colleagues evaluated the safety and efficacy of transradial vs. transfemoral access in consecutive patients enrolled in the angiography/PCI registry at their institution who were treated between January 2007 and August 2010. All patients had a BMI greater than 40 kg/m², which the World Health Organization deems as obesity class III (extreme or morbid obesity). 

Radial Has the Edge

Of the 564 procedures performed in extremely obese patients, 36% (n = 203) were via the transradial route and 64% (n = 361) were performed transfemorally. Transradial access yielded a lower incidence of the combined primary endpoint of bleeding, access site, and nonaccess site complications, driven by reductions in major bleeding and access site injury (table 1).

Table 1. Outcomes and Complications

In terms of nonaccess site complications, there was no difference between the femoral and radial groups (1.7% vs. 2.0%; P = 0.54).

Overall, transradial access resulted in longer procedure times (44.3 ± 25.3 min vs. 30.5 ± 23.0 min; P < 0.001) and fluoroscopy times (12.5 ± 8.2 min vs. 6.7 ± 6.3 min; P < 0.001) compared with transfemoral access, with a strong trend toward greater contrast volume use (P = 0.06). The increased use of fluoroscopy resulted in greater patient radiation exposure with radial access (P < 0.001)

The researchers also divided the groups by coronary angiography or PCI alone and found that femoral angiography procedures were shorter than radial angiography (22.0 ± 10.8 min vs. 35.7 ± 17.3 min; P < 0.001), as were fluoroscopy times (4.9 ± 4.3 min vs. 10.3 ± 7.3 min; P < 0.001). Radial access did not lengthen PCI time, but was associated with a modest increase in fluoroscopy time compared with femoral access (16.9 ± 8.3 min vs. 12.8 ± 8.1 min; P < 0.01). Regardless of procedure type, radial access was not associated with greater contrast use.

Confirmatory Results

According to the study authors, the findings confirm the reductions in bleeding outcomes that have been shown in other studies and add to a growing body of information about the benefits of the radial approach in high-risk populations. 

“In view of the magnitude of the reduction in procedural morbidity, a randomized controlled trial is needed in the [extremely obese] population to definitively establish impact on clinical outcomes,” they add. 

They also point out that the reductions in morbidity come at a cost, namely the increased procedure time and exposure to radiation. For these reasons, increased emphasis should be put on use of radiation shielding and increased operator experience to reduce radiation exposure for both the patient and operator, they add.suit 

Sunil V. Rao, MD, of Duke University Medical Center (Durham, NC), told TCTMD in a telephone interview that the study “adds more to the radial story” because the morbidly obese are a population that has not been studied much. 

“Most trials that we see [of radial PCI] don’t explicitly exclude patients such as these, but the reality is not many of them are approached for trials,” he said. “These extremely obese patients with BMI over 40 are still a relatively small proportion of the population, although it’s growing.”

Benefits Tempered with Caution

Dr. Rao, whose own practice is primarily radial, said data such as these should “serve as a wake-up call” to operators that they should routinely be choosing radial first in extremely obese patients given the clear benefits. Additionally, he said, the radial approach eases some of the logistical problems associated with PCI in obese patients, namely that they can get up and start moving around more quickly rather than having to lay supine following a transfemoral procedure. They also tend to have robust radial pulses and are more likely to be younger, both characteristics that bode well for successful radial procedures, he added. 

Although Dr. Rao said there are few differences in using a radial technique in obese patients versus those of normal weight, imaging poses the greatest challenge.

“For these patients, it does take a tremendous amount of radiation to get a decent image,” he said. “Sometimes there are angulations of the camera that simply won’t work because of how large they are. You really do need to be cognizant of the fact that their size is going to increase procedure time slightly and certainly radiation exposure, as this study shows.” 

For operators without extensive experience in radial procedures, Dr. Rao said, it may be wise to refer extremely obese patients to centers with a high radial volume. 

 

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Source:
Hibbert B, Simard T, Wilson KR, et al. Transradial versus transfemoral artery approach for coronary angiography and percutaneous coronary intervention in the extremely obese. J Am Coll Cardiol Intv. 2012;5:819-826.

 

 

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• Meta-analysis: Transradial Access Cheaper, Safer for Coronary Procedures
• Benefits of Transradial PCI May be Limited to High Volume Centers