Novel valve-in-surgical bioprosthetic transcatheter aortic valve replacement: Undermining iatrogenic coronary obstruction with radiofrequency needle (UNICORN).

An 86-year-old female with history of surgical aortic valve replacement presented with clinical signs of heart failure. Echocardiography revealed a reduction in left ventricular systolic function and severe bioprosthetic aortic valve dysfunction. This is the first reported case of valve-in-valve transcatheter aortic valve replacement with concomitant undermining iatrogenic coronary obstruction with radiofrequency needle procedure in a surgical bioprosthetic valve.

Retrograde chronic total occlusion percutaneous coronary intervention via ipsilateral collaterals.

BACKGROUND: There is limited data on retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) via ipsilateral epicardial collaterals (IEC). AIMS: To compare the clinical and angiographic characteristics, and outcomes of retrograde CTO PCI via IEC versus other collaterals in a large multicenter registry. METHODS: Observational cohort study from the Prospective Global registry for the study of Chronic Total Occlusion Intervention (PROGRESS-CTO). RESULTS: Of 4466 retrograde cases performed between 2012 and 2023, crossing through IEC was attempted in 191 (4.3%) cases with 50% wiring success. The most common target vessel in the IEC group was the left circumflex (50%), in comparison to other retrograde cases, where the right coronary artery was most common (70%). The Japanese CTO score was similar between the two groups (3.13 ± 1.23 vs. 3.06 ± 1.06, p = 0.456); however, the IEC group had a higher Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) score (1.95 ± 1.02 vs. 1.27 ± 0.92, p < 0.0001). The most used IEC guidewire was the SUOH 03 (39%), and the most frequently used microcatheter was the Caravel (43%). Dual injection was less common in IEC cases (66% vs. 89%, p < 0.0001). Technical (76% vs. 79%, p = 0.317) and procedural success rates (74% vs. 79%, p = 0.281) were not different between the two groups. However, IEC cases had a higher procedural complications rate (25.8% vs. 16.4%, p = 0.0008), including perforations (17.3% vs. 9.0%, p = 0.0001), pericardiocentesis (3.1% vs. 1.2%, p = 0.018), and dissection/thrombus of the donor vessel (3.7% vs. 1.2%, p = 0.002). CONCLUSION: The use of IEC for retrograde CTO PCI was associated with similar technical and procedural success rates when compared with other retrograde cases, but higher incidence of periprocedural complications.

A case report of ventricular fibrillation following Shockwave intravascular lithotripsy during percutaneous coronary intervention.

BACKGROUND: Shockwave intravascular lithotripsy (S-IVL) is widely used during percutaneous coronary intervention (PCI) of calcified coronary arteries. Ventricular capture beats during S-IVL are common but arrhythmias are rare. CASE PRESENTATION: A 75-year-old woman was scheduled for PCI to a short, heavily calcified chronic total occlusion of the right coronary artery. After wiring of the occlusion, S-IVL was used to predilated the calcified stenosis. During S-IVL, the patient developed ventricular fibrillation twice. CONCLUSION: To our knowledge, this is only the second reported case of VF during S-IVL. Although very rare, it is important to be aware of this potential and serious complication.

de Winter syndrome or inferior STEMI?

BACKGROUND: The de Winter electrocardiography (ECG) pattern is associated with acute total or subtotal occlusion of the left anterior descending coronary artery (LAD) characterized by upsloping ST-segment depression at the J point in leads V1-V6 without ST-segment elevation. CASE PRESENTATION: We report an atypical style case of the de Winter ECG pattern accompanied by ST elevation in inferior leads. The patient underwent emergency coronary angiography, which revealed total occlusion of the proximal LAD with no observable stenosis in the right coronary artery. CONCLUSION: ECG-related changes in acute total LAD occlusion can present with the de Winter pattern and ST elevation in inferior leads. Recognizing this atypical ECG pattern is critical for immediate reperfusion therapy.

Association between the triglyceride glucose index and coronary collateralization in coronary artery disease patients with chronic total occlusion lesions.

BACKGROUND: Recent studies have substantiated the role of the triglyceride glucose (TyG) index in predicting the prognosis of coronary artery disease (CAD) patients, while no relevant studies have revealed the association between the TyG index and coronary collateralization in the event of coronary chronic total occlusion (CTO). The current study intends to explore whether, or to what extent, the TyG index is associated with impaired collateralization in CAD patients with CTO lesions. METHODS: The study enrolled 1093 CAD patients undergoing cardiac catheterization for at least one CTO lesion. Data were collected from the Beijing Anzhen Hospital record system. The degree of collaterals was determined according to the Rentrop classification system. The correlation between the TyG index and coronary collateralization was assessed. RESULTS: Overall, 318 patients were included in a less developed collateralization (Rentrop classification 0-1) group. The TyG index was significantly higher in patients with impaired collateralization (9.3±0.65 vs. 8.8±0.53, P<0.001). After adjusting for various confounding factors, the TyG index remained correlated with the occurrence of impaired collateralization, with odds ratios (ORs) of 1.59 and 5.72 in the T2 and T3 group compared with the first tertile group (P<0.001). In addition, subgroup analysis showed that higher TyG index values remained strongly associated with increased risk of less developed collateralization. To compare the risk assessment efficacy for the formation of collateralization between the TyG index and other metabolic abnormality indicators, an area under the receiver-operating characteristic (ROC) curve (AUC) was obtained. A significant improvement in the risk assessment performance for impaired collateralization emerged when adding the TyG index into a baseline model. CONCLUSIONS: The increased TyG index is strongly associated with less developed collateralization in CAD patients with CTO lesions and its risk assessment performance is better than single metabolic abnormality indicators.

Recognizing electrocardiographically subtle occlusion myocardial infarction and differentiating it from mimics: Ten steps to or away from cath lab.

It is increasingly evident that the ST-segment elevation (STE) myocardial infarction (MI)/non-STEMI paradigm that equates STEMI with acute coronary occlusion (ACO) is deceptive. This unfortunate paradigm, adhered to by the current guidelines, misses at least one-fourth of the ACOs, and unnecessarily over-triages a similar fraction of the patients to the catheterization laboratory. Accordingly, we have been calling for a new paradigm, the occlusion/nonocclusion MI (OMI/NOMI). Although this new OMI/NOMI paradigm is not limited to an electrocardiogram (ECG), the ECG will remain the cornerstone of this new paradigm because of its speed, repeatability, noninvasive nature, wide availability, and high diagnostic power for OMI. This review provides a step-by-step approach to ECG for the diagnosis of OMI.

Delayed coronary artery occlusion after transcatheter aortic valve replacement and chimney stenting: a case report.

BACKGROUND: Delayed coronary artery occlusion (CAO) is a rare but fatal complication after transcatheter aortic valve replacement, chimney stenting is the standard technique for established CAO or impending CAO. CASE PRESENTATION: We describe a female patient who developed non-ST elevation myocardial infarction after receiving transcatheter aortic valve replacement and chimney stenting 4 months prior. An angiogram revealed delayed coronary artery occlusion with a deformed stent, which was never reported. This patient was subsequently treated with a new chimney stent. CONCLUSIONS: For self-expanding valves, the coronary ostium is protected by chimney stenting, delayed coronary artery occlusion can occur and cause catastrophic complications.

Prevalence of Coronary Artery Disease and Coronary Microvascular Dysfunction in Patients With Heart Failure With Preserved Ejection Fraction.

Importance: Coronary artery disease (CAD) and coronary microvascular dysfunction (CMD) may contribute to the pathophysiologic characteristics of heart failure with preserved ejection fraction (HFpEF). However, the prevalence of CAD and CMD have not been systematically studied. Objective: To examine the prevalence of CAD and CMD in hospitalized patients with HFpEF. Design, Setting, and Participants: A total of 106 consecutive patients hospitalized with HFpEF were evaluated in this prospective, multicenter, cohort study conducted between January 2, 2017, and August 1, 2018; data analysis was performed from March 4 to September 6, 2019. Participants underwent coronary angiography with guidewire-based assessment of coronary flow reserve, index of microvascular resistance, and fractional flow reserve, followed by coronary vasoreactivity testing. Cardiac magnetic resonance imaging was performed with late gadolinium enhancement and assessment of extracellular volume. Myocardial perfusion was assessed qualitatively and semiquantitatively using the myocardial-perfusion reserve index. Main Outcomes and Measures: The prevalence of obstructive epicardial CAD, CMD, and myocardial ischemia, infarction, and fibrosis. Results: Of 106 participants enrolled (53 [50%] women; mean [SD] age, 72 [9] years), 75 had coronary angiography, 62 had assessment of coronary microvascular function, 41 underwent coronary vasoreactivity testing, and 52 received cardiac magnetic resonance imaging. Obstructive epicardial CAD was present in 38 of 75 participants (51%, 95% CI, 39%-62%); 19 of 38 (50%; 95% CI, 34%-66%) had no history of CAD. Endothelium-independent CMD (ie, coronary flow reserve <2.0 and/or index of microvascular resistance ≥25) was identified in 41 of 62 participants (66%; 95% CI, 53%-77%). Endothelium-dependent CMD (ie, abnormal coronary vasoreactivity) was identified in 10 of 41 participants (24%; 95% CI, 13%-40%). Overall, 45 of 53 participants (85%; 95% CI, 72%-92%) had evidence of CMD and 29 of 36 (81%; 95% CI, 64%-91%) of those without obstructive epicardial CAD had CMD. Cardiac magnetic resonance imaging findings included myocardial-perfusion reserve index less than or equal to 1.84 (ie, impaired global myocardial perfusion) in 29 of 41 patients (71%; 95% CI, 54%-83%), visual perfusion defect in 14 of 46 patients (30%; 95% CI, 19%-46%), ischemic late gadolinium enhancement (ie, myocardial infarction) in 14 of 52 patients (27%; 95% CI, 16%-41%), and extracellular volume greater than 30% (ie, diffuse myocardial fibrosis) in 20 of 48 patients (42%; 95% CI, 28%-56%). Patients with obstructive CAD had more adverse events during follow-up (28 [74%]) than those without obstructive CAD (17 [46%]). Conclusions and Relevance: In this cohort study, 91% of patients with HFpEF had evidence of epicardial CAD, CMD, or both. Of those without obstructive CAD, 81% had CMD. Obstructive epicardial CAD and CMD appear to be common and often unrecognized in hospitalized patients with HFpEF and may be therapeutic targets.

Non-high-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio serve as a predictor for coronary collateral circulation in chronic total occlusive patients.

OBJECTIVE: The present study investigated the potential correlation between non-high-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (non-HDL-C/HDL) and the formation of coronary collateral circulation (CCC) in coronary artery disease cases with chronic total occlusive (CTO) lesions. METHODS: Two experienced cardiologists identified and selected patients with CTO lesions for retrospective analysis. The 353 patients were divided into a CCC poor formation group (Rentrop 0-1 grade, n = 209) and a CCC good formation group (Rentrop 2-3 grade, n = 144) based on the Cohen-Rentrop standard. A comparison of non-HDL-C/HDL ratios between the two groups was performed. The Spearman test was used to obtain the correlation between the cholesterol ratio and Rentrop grade. Independent predictors of CCC were analyzed using logistic regression. Receiver operating characteristic (ROC) curve analysis was also performed to quantify the predictive value of research indicator. RESULTS: The non-HDL-C/HDL ratio in the CCC poor formation group was elevated markedly compared to the CCC good formation group [( 3.86 ± 1.40) vs ( 3.31 ± 1.22), P = 0.000]. The Spearman test results indicated that non-HDL-C/HDL negatively correlated with Rentrop grade (r = - 0.115, P = 0.030). Multivariate logistic regression analysis showed that non-HDL-C/HDL ratio was an independent predictor of CCC formation (OR = 1.195, 95%CI = 1.020-1.400, P = 0.027). The area under the curve of ROC for detecting CCC poor formation was 0.611 (95% CI: 0.551-0.671, P = 0.000) with an optimal cut-off value of 2.77. CONCLUSION: Non-HDL-C/HDL negatively correlated with the formation of CCC and served as an independent predictor of CCC formation, which may be used as a biomarker for the evaluation of CCC.

Prognostic Impact of Branch Vessel Involvement on Computed Tomography versus Clinical Presentation of Malperfusion in Patients With Type a Acute Aortic Dissection.

Type A acute aortic dissection (AAD) is a life-threatening disease. The use of contrast-enhanced computed tomography (CT) for diagnosing AAD has increased, and CT can provide pathophysiologic information on dissection such as intramural hematoma (IMH), longitudinal extent of dissection, and branch vessel involvement. However, the prognostic impact of these CT findings is poorly investigated. This multicenter registry included 703 patients with type A AAD. The longitudinal extent of dissection and IMH was determined on CT. Branch vessel involvement was defined as dissection extended into coronary, cerebral, and visceral arteries on CT. The evidence of malperfusion was defined based on clinical presentations. The primary endpoint was in-hospital death. Of 703 patients, 126 (18%) died during hospitalization. Based on contrast-enhanced CT findings, longitudinal extent of dissection was not associated with in-hospital death, while patients with IMH had lower in-hospital mortality than those without (13% vs 22%, p = 0.004). Coronary, cerebral, and visceral artery involvement on CT was found in 6%, 55%, and 32%. In patients with coronary artery involvement, 90% had clinical coronary malperfusion, while only 25% and 21% of patients with cerebral and visceral artery involvement had clinical evidence of corresponding organ malperfusion. Multivariable analysis showed evidence of malperfusion as a significant factor associated with in-hospital mortality. In conclusions, branch vessel involvement on CT was not always associated with end-organ malperfusion in patients with type A AAD, especially in cerebral and visceral arteries. Clinical evidence of malperfusion was significantly associated with in-hospital mortality beyond branch vessel involvement on CT.

Impact of acute total occlusion of the culprit artery on outcome in NSTEMI based on the results of a large national registry.

BACKGROUND: The impact of acute total occlusion (TO) of the culprit artery in non-ST-segment elevation myocardial infarction (NSTEMI) is not fully established. We aimed to evaluate the clinical and angiographic phenotype and outcome of NSTEMI patients with TO (NSTEMITO) compared to NSTEMI patients without TO (NSTEMINTO) and those with ST-segment elevation and TO (STEMITO). METHODS: Demographic, clinical and procedure-related data of patients with acute myocardial infarction who underwent percutaneous coronary intervention (PCI) between 2014 and 2017 from the Polish National Registry were analysed. RESULTS: We evaluated 131,729 patients: NSTEMINTO (n = 65,206), NSTEMITO (n = 16,209) and STEMITO (n = 50,314). The NSTEMITO group had intermediate results compared to the NSTEMINTO and STEMITO groups regarding mean age (68.78 ± 11.39 vs 65.98 ± 11.61 vs 64.86 ± 12.04 (years), p < 0.0001), Killip class IV on admission (1.69 vs 2.48 vs 5.03 (%), p < 0.0001), cardiac arrest before admission (2.19 vs 3.09 vs 6.02 (%), p < 0.0001) and death during PCI (0.43 vs 0.97 vs 1.76 (%), p < 0.0001)-for NSTEMINTO, NSTEMITO and STEMITO, respectively. However, we noticed that the NSTEMITO group had the longest time from pain to first medical contact (median 4.0 vs 5.0 vs 2.0 (hours), p < 0.0001) and the lowest frequency of TIMI flow grade 3 after PCI (88.61 vs 83.36 vs 95.57 (%), p < 0.0001) and that the left circumflex artery (LCx) was most often the culprit lesion (14.09 vs 35.86 vs 25.42 (%), p < 0.0001). CONCLUSIONS: The NSTEMITO group clearly differed from the NSTEMINTO group. NSTEMITO appears to be an intermediate condition between NSTEMINTO and STEMITO, although NSTEMITO patients have the longest time delay to and the worst result of PCI, which can be explained by the location of the culprit lesion in the LCx.

Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs.

The development of heart failure is the most powerful predictor of long-term mortality in patients surviving acute myocardial infarction (MI). There is an unmet clinical need for prevention and therapy of post-myocardial infarction heart failure (post-MI HF). Clinically relevant pig models of post-MI HF are prerequisites for final proof-of-concept studies before entering into clinical trials in drug and medical device development. Here we aimed to characterize a closed-chest porcine model of post-MI HF in adult Göttingen minipigs with long-term follow-up including serial cardiac magnetic resonance imaging (CMRI) and to compare it with the commonly used Landrace pig model. MI was induced by intraluminal balloon occlusion of the left anterior descending coronary artery for 120 min in Göttingen minipigs and for 90 min in Landrace pigs, followed by reperfusion. CMRI was performed to assess cardiac morphology and function at baseline in both breeds and at 3 and 6 months in Göttingen minipigs and at 2 months in Landrace pigs, respectively. Scar sizes were comparable in the two breeds, but MI resulted in a significant decrease of left ventricular ejection fraction (LVEF) only in Göttingen minipigs, while Landrace pigs did not show a reduction of LVEF. Right ventricular (RV) ejection fraction increased in both breeds despite the negligible RV scar sizes. In contrast to the significant increase of left ventricular end-diastolic (LVED) mass in Landrace pigs at 2 months, Göttingen minipigs showed a slight increase in LVED mass only at 6 months. In summary, this is the first characterization of post-MI HF in Göttingen minipigs in comparison to Landrace pigs, showing that the Göttingen minipig model reflects post-MI HF parameters comparable to the human pathology. We conclude that the Göttingen minipig model is superior to the Landrace pig model to study the development of post-MI HF.

Metabolic syndrome and its components reduce coronary collateralization in chronic total occlusion: An observational study.

BACKGROUND: Metabolic syndrome (MetS) is an independent risk factor for the incidence of cardiovascular diseases. We investigated whether or to what extent MetS and its components was associated with coronary collateralization (CC) in chronic total occlusion (CTO). METHODS: This study involved 1653 inpatients with CTO. Data on demographic and clinical characteristics were collected by cardiovascular doctors. The CC condition was defined by the Rentrop scoring system. Subgroup analysis, mixed model regression analysis, scoring systems and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: Overall, 1653 inpatients were assigned to the poor CC group (n = 355) and good CC group (n = 1298) with or without MetS. Compared to the good CCs, the incidence of MetS was higher among the poor CCs for all patients. Poor collateralization was present in 7.6%, 14.2%, 19.3%, 18.2%, 35.6% and 51.1% of the six groups who met the diagnostic criteria of MetS 0, 1, 2, 3, 4 and 5 times, respectively. For multivariable logistic regression, quartiles of BMI remained the risk factors for CC growth in all subgroups (adjusted OR = 1.755, 95% CI 1.510-2.038, P < 0.001 all patients; adjusted OR = 1.897, 95% CI 1.458-2.467, P < 0.001 non-MetS; and adjusted OR = 1.814, 95% CI 1.482-2.220, P < 0.001 MetS). After adjustment for potential confounding factors, MetS was an independent risk factor for CC growth in several models. Assigning a score of one for each component, the AUCs were 0.629 (95% CI 0.595-0.662) in all patients, 0.656 (95% CI 0.614-0.699) in MetS patients and 0.569 (95% CI 0.517-0.621) in non-MetS patients by receiver operating characteristic analysis. CONCLUSIONS: MetS, especially body mass index, confers a greater risk of CC formation in CTO. The value of scoring systems should be explored further for CTO.

The impact of successful chronic total occlusion percutaneous coronary intervention on long-term clinical outcomes in real world.

BACKGROUND: Coronary chronic total occlusions (CTOs) are related to increased risk of adverse clinical outcomes. The optimal treatment strategy for CTO has not been well established. We sought to examine the impact of CTO percutaneous coronary intervention (PCI) on long-term clinical outcome in the real world. METHODS: A total of 592 patients with CTO were enrolled. 29 patients were excluded due to coronary artery bypass grafting (CABG). After exclusion, 563 patients were divided into the no-revascularized group (CTO-NR group, n = 263) and successful revascularized group (CTO-R group, n = 300). The primary endpoint was cardiac death; secondary endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, cardiac death, recurrent myocardial infarction, target lesion revascularization, re-hospitalization, heart failure, and stroke. RESULTS: Percent of Diabetes mellitus (53.2% vs 39.7), Chronic kidney disease (8.7% vs 3.7%), CABG history (7.6% vs 1%), three vessel disease (96.2% vs 90%) and left main coronary artery disease (25.1% vs 13.7%) was significantly higher in the CTO-NR group than in success PCI group (all P < 0.05). Moreover, the CTO-NR group has the lower ejection fraction (EF) (0.58 ± 0.11 vs 0.61 ± 0.1, p = 0.001) and fraction shortening (FS) (0.31 ± 0.07 vs 0.33 ± 0.07, p = 0.002). At a median follow-up of 12 months, CTO revascularization was superior to CTO no-revascularization in terms of cardiac death (adjusted hazard ratio [HR]: 0.27, 95% conference interval [CI] 0.11-0.64). The superiority of CTO revascularization was consistent for MACCE (HR: 0.55, 95% CI 0.35-0.79). At multivariable Cox hazards regression analysis, CTO revascularization remains one of the independent predictors of lower risk of cardiac death and MACCE. CONCLUSIONS: Successful revascularization by PCI may bring more clinical benefits. The presence of low left ventricular ejection fraction (LVEF) and LM-disease was associated with an incidence of cardiac death; CTO revascularization was a protected predictor of cardiac death. Successful revascularization by PCI offered CTO patients more clinical benefits, manifested by lower incidence of cardiac death during follow-up. The presence of LVEF < 0.5 and left main coronary artery disease (LM disease) was associated with an incidence of cardiac death; CTO revascularised was a protected predictor of cardiac death.

Coronary Collateral Flow Index Is Correlated With the Palmar Collateral Flow Index: Indicating Systemic Collateral Coherence in Individual Patients-Brief Report.

[Figure: see text].

Long-Term Outcomes of Percutaneous Coronary Intervention for Patients With In-Stent Chronic Total Occlusion Versus De Novo Chronic Total Occlusion.

Limited data are available on long-term outcomes and health status in the treatment of in-stent coronary chronic total occlusion (IS-CTO) and de novo coronary chronic total occlusion (de novo CTO). This study compared the long-term clinical outcomes and health status of percutaneous coronary intervention (PCI) for patients with IS-CTO versus patients with de novo CTO in the drug-eluting stent era. We screened 483 consecutive patients with 1 CTO lesion, including 81 patients with IS-CTO and 402 patients with de novo CTO. Propensity score matching was used to balance baseline characteristics between the 2 groups. The clinical end point was major adverse cardiac events (MACE). The success rates of CTO lesion revascularization were similar in both groups. In the propensity score-matched patients, after a median follow-up of 36 months, MACE was observed in 32.8% of patients with IS-CTO versus 13.5% of the patients with de novo CTO (P < .001), mainly driven by target-vessel revascularization (21.9% vs 6.7%; P < .01). Moreover, patients with IS-CTO had significantly worse Seattle Angina Questionnaire anginal stability scores than the patients with de novo CTO. In conclusion, patients with IS-CTO after PCI had a worse clinical outcome, mainly MACE, and a poorer anginal stability in the long term than patients with de novo CTO.

Relation of Obstructive Sleep Apnea in Patients With a Coronary Chronic Total Occlusion to Coronary Collaterals and Mortality.

A chronic total occlusion (CTO) is frequently identified in patients undergoing coronary angiography. The prognostic implications of intermittent hypoxia from obstructive sleep apnea (OSA) on patients with a CTO, and effects on collateral recruitment are unknown. The aim of this study was to determine the prevalence, vascular effects, and prognostic implications of the presence of OSA in patients with a CTO. Patients with a CTO between July 2010 and December 2019 were reviewed. Electronic medical records were accessed to determine documented patient history of OSA, demographics, and clinical course. Patients with robust collateral recruitment were defined as Rentrop grade 2 or 3. A total of 948 patients were included in the study, of which 127 (13.4%) had a documented history of OSA. These patients were younger (67.0 years vs 70.6 years, p < 0.01), had a higher body mass index (29.6 kg/m2 vs 26.7 kg/m2, p < 0.0001), higher rates of hypertension (91.3% vs 83.2%, p < 0.05), higher rates of smokers (63.3% vs 49.0%, p < 0.01) and more use of ß-blockers (79% vs 68.5%, p < 0.05) and statins (92.7% vs 82.1%, p < 0.01). A documented history of OSA was independently associated with robust collaterals (OR 3.0 95%CI 1.5 to 5.8, p < 0.01) and lower mortality (HR 0.3 95% CI 0.1 to 0.7, p < 0.01) with a mean survival of 10.8 years, as compared to 8.1 years (log rank p < 0.0001). In conclusion, in patients with a CTO, documented OSA is independently associated with more robust coronary collaterals and lower mortality. The possible cardioprotective implications of intermittent hypoxia in OSA, as well as treatment effect requires further investigation.