Contemporary Management Before Chronic Total Occlusion Percutaneous Coronary Interventions: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

BACKGROUND: Guidelines recommend maximal antianginal medical therapy before attempted coronary artery chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The degree to which this occurs in contemporary practice is unknown. We aimed to characterize the frequency and variability of preprocedural use of antianginal therapy and stress testing within 3 months before PCI of CTO (CTO PCI) across a nationally integrated health care system. METHODS: We identified patients who underwent attempted CTO PCI from January 2012 to September 2018 within the Veterans Affairs Healthcare System. Patients were categorized by management before CTO PCI: presence of ≥2 antianginals, stress testing, and ≥2 antianginals and stress testing within 3 months of PCI attempt. Multivariable logistic regression and inverse propensity weighting were used for adjustment before trimming, with median odds ratios calculated for variability estimates. RESULTS: Among 4250 patients undergoing attempted CTO PCI, 40% received ≥2 antianginal medications and 24% underwent preprocedural stress testing. The odds of antianginal therapy with more than one medication before CTO PCI did not change over the years of the study (odds ratio [OR], 1.0 [95% CI, 0.97-1.04]), whereas the odds of undergoing preprocedural stress testing decreased (OR, 0.97 [95% CI, 0.93-0.99]), and the odds of antianginal therapy with ≥2 antianginals and stress testing did not change (OR, 0.98 [95% CI, 0.93-1.04]). Median odds ratios (MOR) showed substantial variability in antianginal therapy across hospital sites (MOR, 1.3 [95% CI, 1.26-1.42]) and operators (MOR, 1.35 [95% CI, 1.26-1.63]). Similarly, preprocedural stress testing varied significantly by site (MOR, 1.68 [95% CI, 1.58-1.81]) and operator (MOR, 1.80 [95% CI, 1.56-2.38]). CONCLUSIONS: Just under half of patients received guideline-recommended management before CTO PCI, with significant site and operator variability. These findings suggest an opportunity to reduce variability in management before CTO PCI.

Hyperbaric oxygenation improves redox control and reduces mortality in the acute phase of myocardial infarction in a rat model.

Among the mechanisms of action of hyperbaric oxygenation (HBO), the chance of reducing injury by interfering with the mechanisms of redox homeostasis in the heart leads to the possibility of extending the period of viability of the myocardium at risk. This would benefit late interventions for reperfusion to the ischemic area. The objective of the present study was to investigate the changes in the redox system associated with HBO therapy maintained during the first hour after coronary occlusion in an acute myocardial infarction (MI) rat model. Surviving male rats (n=105) were randomly assigned to one of three groups: Sham (SH=26), myocardial infarction (MI=45) and infarction+hyperbaric therapy (HBO=34, 1 h at 2.5 atm). After 90 min of coronary occlusion, a sample of the heart was collected for western blot analysis of total protein levels of superoxide dismutase, catalase, peroxiredoxin and 3­nitrotyrosine. Glutathione was measured by enzyme­linked immunosorbent assay (ELISA). The detection of the superoxide radical anion was carried out by oxidation of dihydroethidium analyzed with confocal microscopy. The mortality rate of the MI group was significantly higher than that of the HBO group. No difference was noted in the myocardial infarction size. The oxidized/reduced glutathione ratio and peroxiredoxin were significantly higher in the SH and MI when compared to the HBO group. Superoxide dismutase enzymes and catalase were significantly higher in the HBO group compared to the MI and SH groups. 3­Nitrotyrosine and the superoxide radical were significantly lower in the HBO group compared to these in the MI and SH groups. These data demonstrated that hyperbaric oxygenation therapy decreased mortality by improving redox control in the hearts of rats in the acute phase of myocardial infarction.

Excimer laser atherectomy to overcome intraprocedural obstacles in chronic total occlusion percutaneous intervention: Case examples.

Technical advances and the development of the Hybrid algorithm have been associated with higher success rates in chronic total occlusion percutaneous coronary intervention (CTO-PCI). Nevertheless, there are still intraprocedural obstacles that result in failure or prolonged procedure time. The Excimer coronary laser (EL) has been repurposed in CTO-PCI to overcome such obstacles. This case series illustrates the use of the EL in four technically complex scenarios including the balloon resistant lesion, the impenetrable proximal cap, device resistance in stent restenosis, and difficulty with device tracking in the subintima.

Hyperbaric oxygenation applied immediately after coronary occlusion reduces myocardial necrosis and acute mortality in rats.

1. Because in ischaemia there is a critical lack of O2, it has been reasoned that increasing O2 delivery to the ischaemic myocardium could serve as adjunctive therapy for acute myocardial infarction (MI). Accordingly, in the present study, the effect of early hyperbaric oxygenation (HBO) on mortality and MI size after coronary occlusion was examined in rats. 2. After coronary occlusion, male Wistar rats were randomly assigned to receive either HBO for 1 h in a hyperbaric chamber (100% O(2) at 253 kPa; n = 106) or ambient O2 as the control (n = 111). The extent of myocardial necrosis was assessed (triphenyltetrazolium) immediately after treatment in the HBO (n = 50) and control (n = 47) groups. The remaining rats were evaluated 24 h after occlusion to enable calculation of MI size and mortality. 3. Immediately after therapy, the size of the MI was significantly greater in the control group compared with that in the HBO group (40 +/- 3 vs 27 +/- 2% of the left ventricle (LV), respectively; P < 0.001). The 24 h mortality of control rats was higher than that of HBO rats (34 vs 16%, respectively; P = 0.02). Control rats that survived 24 h had a larger MI than did HBO rats that survived 24 h (40 +/- 4 vs 29 +/- 3% of the LV, respectively; P = 0.005). Furthermore, large necrotic areas (> 40% of the LV) were more frequent in control than HBO rats (55 vs 27% of infarcted hearts, respectively; P = 0.01). There was less pulmonary congestion observed in HBO rats compared with control rats. 4. In conclusion, early therapy with HBO during the onset of an acute ischaemic event decreases the necrotic area and reduces acute mortality. These data support further investigation of HBO as an adjuvant therapy for acute MI.

Electrophysiological effects of late percutaneous coronary intervention for infarct-related coronary artery occlusion: the Occluded Artery Trial-Electrophysiological Mechanisms (OAT-EP).

BACKGROUND: The Occluded Artery Trial-Electrophysiological Mechanisms (OAT-EP) tested the hypothesis that opening a persistently occluded infarct-related artery by percutaneous coronary intervention and stenting (PCI) after the acute phase of myocardial infarction compared with optimal medical therapy alone reduces markers of vulnerability to ventricular arrhythmias. METHODS AND RESULTS: Between April 2003 and December 2005, 300 patients with an occluded native infarct-related artery 3 to 28 days (median, 12 days) after myocardial infarction were randomized to PCI or optimal medical therapy. Ten-minute digital Holter recordings were obtained before randomization, at 30 days, and at 1 year. The primary end point was the change in alpha1, a nonlinear heart rate variability parameter, between baseline and 1 year. Major secondary end points were the changes in the filtered QRS duration on the signal-averaged ECG and variability in T-wave morphology (T-wave variability) between baseline and 1 year. There were no significant differences in the changes in alpha1 (-0.04; 95% CI, -0.12 to 0.04), filtered QRS (2.2 ms; 95% CI, -1.4 to 5.9 ms), or T-wave variability (3.0 microV; 95% CI, -4.8 to 10.7 microV) between the PCI and medical therapy groups (medical therapy change minus PCI change). Multivariable analysis revealed that the results were unchanged after adjustment for baseline clinical variables and medication treatments during the Holter recordings. CONCLUSIONS: PCI with stenting of a persistently occluded infarct-related artery during the subacute phase after myocardial infarction compared with medical therapy alone had no significant effect on changes in heart rate variability, the time-domain signal-averaged ECG, or T-wave variability during the first year after myocardial infarction. These findings are consistent with the lack of clinical benefit, including no reduction in sudden death, with PCI for stable patients with persistently occluded infarct-related arteries after myocardial infarction in the main OAT.