Routine intracoronary beta-irradiation. Acute and one year outcome in patients at high risk for recurrence of stenosis

Association of Urinary Strontium with Cardiovascular Disease Among the US Adults: A Cross-Sectional Analysis of the National Health and Nutrition Examination Survey

Previous studies have demonstrated the effects of environmental metals on the cardiovascular system. However, the relationship of strontium (Sr) to cardiovascular disease (CVD) in the general population has not been established. This cross-sectional study aimed to investigate the association between urinary Sr (U-Sr) and CVD in the US adults using data of 5255 participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2016. Multivariable logistic regression and restricted cubic spline (RCS) regression were performed to assess the association between U-Sr and CVD. After multivariable adjustments, compared to the lowest quartile, the adjusted odds ratios (ORs) of CVD with 95% confidence intervals (CIs) across the quartiles were 0.65 (0.46, 0.92), 0.87 (0.61, 1.25), and 0.78 (0.55, 1.10). RCS plot revealed a nonlinear relationship between U-Sr levels and CVD (P for nonlinearity = 0.004). Threshold effect analysis identified the inflection point of U-Sr for the curve was 90.18 μg/g urinary creatinine (μg/g UCr). Each 1-unit increase in U-Sr was associated with a 1.1% decrease in CVD (OR 0.989; 95% CI 0.980-0.998) on the left side of the inflection point, but no significant association was observed on the right side of the inflection point. This study suggests a nonlinear association of U-Sr with CVD prevalence in the US general adults. These findings may have positive implications for the determination of appropriate Sr levels for public cardiovascular health. Given the cross-sectional study design, further prospective studies are warranted.

A European multi‐center trial investigating the anti‐restenotic effect of intravascular sonotherapy after stenting of de novo lesions (EUROSPAH: EUROpean Sonotherapy Prevention of Arterial Hyperplasia)

BACKGROUND

Intravascular sonotherapy (IST) reduces neointimal hyperplasia post-stenting in animal studies. Euro-SPAH is a multi-center, double blind, randomized trial investigating the efficacy of IST to reduce in-stent late loss.

METHODS

Patients with angina or silent ischaemia with stented de novo lesions were randomised to sham or IST. The sample size had a 90% power to detect a late loss difference of 0.21 mm at 6 months. The secondary endpoints were MACE at 1, 6, 12 months and neo-intimal hyperplasia on IVUS at 6 months.

RESULTS

At 23 sites in Europe, 403 patients were randomized, with successful treatment with sham or IST in 95.6%. There were no significant differences between the groups in terms of baseline demographics or lesion characteristics. Angiographic follow-up was obtained in 89%. In-stent late loss was not significantly different. The restenosis rate at 6 months was 23% in the IST group versus 25% in the sham group. The IVUS measurements confirm the absence of effect of IST on neointimal hyperplasia. At one year, the event-free survival did not significantly differ between the two groups.

CONCLUSION

The use of sonotherapy following stent implantation in de novo lesions does not reduce intra-stent neointimal hyperplasia, or effect the angiographic restenosis rate compared to sham treatment.

Comparison between sirolimus-eluting stents and intracoronary catheter-based beta radiation for the treatment of in-stent restenosis

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a beta-Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 +/- 1.1 and 12.1 +/- 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 +/- 0.45 vs 0.34 +/- 0.46 mm, p = 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 +/- 0.13 vs 0.57 +/- 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 +/- 0.32 vs 0.16 +/- 0.42 mm, p = 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.

Intracoronary Brachytherapy for Treatment of In-Stent Restenosis

Randomized, double-blind, placebo-controlled trials have demonstrated that intracoronary brachytherapy is more efficacious than placebo in reducing death, myocardial infarction, and target vessel revascularization at long-term follow up of patients with in-stent restenosis. Intracoronary brachytherapy is efficacious in treating totally occluded in-stent restenotic lesions, in treating de novo and in-stent restenotic lesions in saphenous vein grafts, in treating diffuse in-stent restenosis, in treating native coronary ostial in-stent restenotic lesions, in treating patients with diabetes with in-stent restenosis, in treating patients at high-risk for recurrence of restenosis, in treating elderly patients, and in treating patients who failed intracoronary radiation. Beta and gamma intracoronary brachytherapy are equally effective in treating in-stent restenosis. Long-term aspirin and clopidogrel should be administered for at least 1 year to reduce late vessel thrombosis. Inadequate radiation may cause edge stenosis.

Adventitial response to intravascular brachytherapy in a rabbit model of restenosis

BACKGROUND

The incidence of late major adverse cardiac events (MACE) after coronary brachytherapy is higher than in controls. Because expansive remodeling has been shown to correlate with poor clinical outcome after vascular interventions, we studied adventitial changes after intravascular irradiation in a rabbit model.

METHODS

Twenty normolipidemic rabbits underwent balloon injury in both external iliac arteries. One artery was assigned for subsequent irradiation with a 90Y source (15 Gy or 30 Gy at 0.5 mm in the vessel wall). After four weeks morphometric measurements were made and cell density and collagen amount determined. Staining for Ki67 identified proliferating cells; apoptotic cells were identified by TUNEL staining. Proliferative and apoptotic indices were calculated as the number of respective positive cells/total cell count x100.

RESULTS

The neointimal area decreased to 0.27 +/- 0.3 mm2 after irradiation compared with 0.55 +/- 0.2 mm2 in controls (p=0.007), whereas adventitial area increased from 0.62 +/- 0.3 mm2 to 0.87 +/- 0.3 mm2 (p=0.02). Irradiation reduced both the proliferative (0.95 +/- 2.6 vs. 3.73 +/- 4.7, p=0.026) and apoptotic (0.006 +/- 0.02 vs. 0.107 +/- 0.2, p=0.03) indices in the neointima, but not in the other arterial-wall layers. Collagen amount and arterial remodeling did not differ between the groups. There was no difference between 15 and 30 Gy in any of the parameters, although adventitial thickening was more pronounced in the high-dose group.

CONCLUSIONS

In normolipidemic rabbits, intravascular beta-irradiation after balloon angioplasty is associated with an increase in neoadventitia and a reduction of neointima. It is conceivable that this phenomenon may contribute to the increased incidence of late MACE after vascular brachytherapy.