The radioprotective effect of the Cathpax® AIR cabin during interventional cardiology procedures.

BACKGROUND: The use of ionizing radiation during cardiac catheterization interventions adversely impacts the medical staff. Traditional radiation protection equipment is only partially effective. The Cathpax® radiation protection cabin (RPC) has proven to significantly reduce radiation exposure in electrophysiological and neuroradiology interventions. Our objective was to analyze whether the Cathpax® RPC reduces radiation dose in coronary and cardiac structural interventions in unselected real-world procedures. METHODS AND RESULTS: In this nonrandomized all-comers prospective study, 119 consecutive cardiac interventional procedures were alternatively divided into two groups: the RPC group (n = 59) and the non-RPC group (n = 60). No significant changes in the characteristics of patients and procedures, average contrast volume, air kerma (AK), dose area-product (DAP) and fluoroscopy time between both groups were apparent. In the RPC group, the first-operator relative radiation exposure was reduced by 78% at the chest and by 70% at the wrist. This effect was consistent during different types of procedures including complex percutaneous interventions and structural procedures. CONCLUSIONS: Our study demonstrates, for the first time, that the Cathpax® cabin significantly and efficiently reduces relative operator radiation exposure during different types of interventional procedures, confirming its feasibility in a real-world setting.

Coronary Flow Reserve and Myocardial Resistance Reserve Changes After Transcatheter Aortic Valve Implantation in Aortic Stenosis.

Aortic valve stenosis (AS) induces an alteration in hemodynamic conditions that are responsible for coronary microvasculature impairment. Relief of AS by transcatheter aortic valve implantation (TAVI) is expected to improve the coronary artery hemodynamic. We aimed to assess the midterm effects of TAVI in coronary flow reserve (CFR) and myocardial resistance reserve (MRR) by a continuous intracoronary thermodilution technique. At-rest and hyperemic coronary flow was measured by a continuous thermodilution technique in 23 patients with AS and compared with that in 17 matched controls, and repeated 6 ± 3 months after TAVI in 11 of the patients with AS. In patients with AS, absolute coronary flow at rest was significantly greater, and absolute resistance at rest was significantly less, than in controls (p <0.01 for both), causing less CFR and MRR (1.73 ± 0.4 vs 2.85 ± 1.1, p <0.01 and 1.95 ± 0.4 vs 3.22 ± 1.4, p <0.01, respectively). TAVI implantation yielded a significant 35% increase in CFR (p >0.01) and a 39% increase in MRR (p <0.01) driven by absolute coronary flow at rest reduction (p = 0.03). In patients with AS, CFR and MRR determined by continuous thermodilution are significantly impaired. At 6-month follow-up, TAVI improves these indexes and partially relieves the pathophysiologic alterations, leading to a partial restoration of CFR and MRR.

Radiation protection for the interventional cardiologist: Practical approach and innovations.

Use of ionizing radiation during cardiac catheterization interventions adversely impacts both the patients and medical staff. In recent years, radiation dose in cardiac catheterization interventions has become a topic of increasing interest in interventional cardiology and there is a strong interest in reducing radiation exposure during the procedures. This review presents the current status of radiation protection in the cardiac catheterization laboratory and summarizes a practical approach for radiation dose management for minimizing radiation exposure. This review also presents recent innovations that have clinical potential for reducing radiation during cardiac interventions.

Continuous Thermodilution Method to Assess Coronary Flow Reserve.

Coronary flow reserve (CFR) is a well-validated flow-based physiological parameter that has shown value in clinical risk stratification. CFR can be invasively assessed, classically by Doppler and, more recently, by thermodilution with saline boluses (CFRthermo-bolus). Alternatively, continuous thermodilution is a novel operator-independent, highly-reproducible technique to invasively quantify maximum absolute coronary flow (AF). This study aimed to assess the feasibility of this method to quantify resting AF and to determine CFR (CFRThermo-infusion) as compared with CFRthermo-bolus. Sixty-two consecutive patients with suspicion of coronary disease and absence of significant epicardial lesions were prospectively investigated. AF at maximal hyperemia (20 mL/min) and at lower infusion rates (6-8-10-12 mL/min) were systematically measured using a dedicated catheter and a temperature/pressure guidewire. The absence of baseline Pd/Pa decrease at 6 (0.15 ± 0.2%), 8 (0.17 ± 0.18%) and 10 mL/min (0.2 ± 0.12%) demonstrated absence of hyperemia at ≤10 mL/min (all p = NS). However, at 12 mL/min hyperemia was confirmed by a significant decrease in Pd/Pa (1.3 ± 1.5%, p <0.01) and increase in AF from 10 mL/min to 12 mL/min (31.4 ± 28.1 mL, p <0.05). All curve tracings at 10 mL/min (129/129, 100%) were adequate versus only (7/15, 53%) and (15/18, 17%) at 6 mL/min, and 8 mL/min, respectively, and this infusion-rate was considered to determine resting-AF. CFRThermo-infusion was determined as the ratio of hyperemic-AF (20 mL/min) by resting-AF (10 mL/min). Mean CFRThermo-infusion was 2.56 ± 0.9 and CFRthermo-bolus 2.49 ± 1. Both parameters showed a good correlation (r = 0.76; p <0.001) and intraclass agreement (ICC = 0.76; p <0.001).The continuous thermodilution method enables to quantify resting-AF providing a novel clinical tool to determine CRF. CFRThermo-infusion shows a good correlation with CFRthermo-bolus..

Contrast FFR plus intracoronary injection of nitro-glycerine accurately predicts FFR for coronary stenosis functional assessment.

BACKGROUND: Fractional flow reserve (FFR) is the "gold standard" for assessing the physiological significance of coronary disease. In the last decade, several alternative adenosine-free indexes have been proposed in order to facilitate the dissemination of the functional evaluation of coronary stenosis. Our aim was to investigate whether radiographic contrast plus intracoronary nitroglycerin (cFFR-NTG) can predict functional assessment of coronary stenosis offering superior diagnostic agreement with FFR compared to non-hyperemic indexes and contrast mediated FFR (cFFR). METHODS: Three hundred twenty-nine lesions evaluated with pressure wire in 266 patients were prospectively included in this multicenter study. RESULTS: The ROC curves for cFFR-NTG using an FFR≤0.80 showed a higher accuracy in predicting FFR (AUC=0.97) than resting Pd/Pa (AUC=0.90, P<0.01) and cFFR (AUC=0.93.5, P<0.01). A significant (P<0.01) strong correlation was found between FFR and the four analyzed indexes: Pd/Pa (r=0.78); iFR/RFR (r=0.73); cFFR(r=0.89) and cFFR-NTG (r=0.93). cFFR-NTG showed the closest agreement at Bland-Altman analysis. The cFFR-NTG cut off value >0.84 showed the highest negative predictive value (88%), specificity (91%), sensitivity (94%) and accuracy (92%) of the studied indexes. CONCLUSIONS: Submaximal hyperemic adenosine-free indexes are an efficient alternative to adenosine for the physiological assessment of epicardial coronary disease. The most accurate index in predicting the functional significance of coronary stenosis using FFR as reference was cFFR-NTG.

Factibilidad de la cuantificación del flujo coronario absoluto y de la resistencia microvascular en la miocardiopatía de tako-tsubo / Feasibility of absolute coronary blood flow and microvascular resistance quantification in tako-tsubo cardiomyopathy

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