Reduction in operator radiation exposure during transradial coronary procedures using a simple lead rectangle.

OBJECTIVES: Transradial access for percutaneous coronary intervention (PCI) reduces procedural complications however, there are concerns regarding the potential for increased exposure to ionizing radiation to the primary operator. We evaluated the efficacy of a lead-attenuator in reducing radiation exposure during transradial PCI. METHODS AND RESULTS: This was a non-randomized, prospective, observational study in which 52 consecutive patients were assigned to either standard operator protection (n = 26) or the addition of the lead attenuator across their abdomen/pelvis (n = 26). In the attenuator group patients were relatively older with a higher prevalence of peripheral vascular disease (67.9 vs 58.7 p = 0.0292 and 12% vs 7.6% p < 0.001 respectively). Despite similar average fluoroscopy times (12.3 ± 9.8 min vs. 9.3 ± 5.4 min, p = 0.175) and average examination doses (111866 ± 80790 vs. 91,268 ± 47916 Gycm2, p = 0.2688), the total radiation exposure to the operator, at the thyroid level, was significantly lower when the lead-attenuator was utilized (20.2% p < 0.0001) as compared to the control group. Amongst the 26 patients assigned to the lead-attenuator, there was a significant reduction in measured radiation of 94.5% (p < 0.0001), above as compared to underneath the lead attenuator. CONCLUSIONS: Additional protection with the use of a lead rectangle-attenuator significantly lowered radiation exposure to the primary operator, which may confer long-term benefits in reducing radiation-induced injury. ADVANCES IN KNOWLEDGE: This is the first paper to show that a simple lead attenuator almost completely reduced the scattered radiation at very close proximity to the patient and should be considered as part of the standard equipment within catheterization laboratories.

Respiratory stress response: a novel diagnostic method for detection of significant coronary artery disease from finger pulse wave analysis during brief respiratory exercise.

INTRODUCTION: Respiratory maneuvers can uncover manifestations of myocardial ischemia. Some pulse wave characteristics are associated with significant coronary artery disease (S-CAD). An innovative test using the respiratory stress response (RSR) has been developed for the detection of S-CAD based on spectral analysis of finger pulse wave oscillations measured using photoplethysmography (PPG) during deep, paced breathing at a rate of 6 breaths per minute (0.1 Hz) for 70 seconds. We evaluated this test (RSR) as an indicator of S-CAD. METHODS: The study consisted of 2 stages--feasibility and validation--assessing RSR in patients referred for coronary angiography. RSR was calculated by proprietary software analysis of the relative spectral power of the respiratory peak area at 0.1 Hz. The coronary angiograms were analyzed visually (stage I) and by quantitative coronary angiography (stage II) by 1 cardiologist blinded to the RSR results. S-CAD was defined as luminal stenosis >70% of at least 1 coronary artery or LM stenosis >50%. RESULTS: A total of 193 consecutive patients (stage I: 98 and stage II: 95) with a mean age of 63.2 +/- 11.9 years, 70% men, 112 (58%) with S-CAD, were included. S-CAD patients had significantly lower RSR compared with patients without S-CAD, P < 0.001. RSR yielded a sensitivity of 83% (95% confidence interval = 75-90) and specificity of 70% (95% confidence interval = 59-80) for indicating S-CAD. Multivariate logistic regression analysis, adjusted for risk factors, showed that RSR is a strong independent indicator of S-CAD [OR = 18.9 (7.2-49.5), P < 0.001]. CONCLUSION: Reduced RSR is an accurate noninvasive indicator of S-CAD.