The myocardium supplied by a chronic total occlusion is a persistently ischemic zone.

UNLABELLED: Well-developed collaterals to a myocardial segment supplied by a chronic total occlusion (CTO) and/or left ventricular dysfunction in the CTO regions in patients with chronic stable angina suggest that severe ischemia is unlikely to be present. We evaluated the presence and severity of ischemia using fractional flow reserve (FFR) of the myocardium supplied by a CTO in patients and compared the results with a non-CTO control group. METHODS: Patients undergoing FFR and successful percutaneous coronary intervention (PCI) of a CTO were evaluated and compared to a matched non-CTO control group. RESULTS: One hundred patients were included (50 CTO/50 controls). CTO lesions were longer (31.6 ± 18.9 vs 20.2 ± 14.9 mm, P = 0.004) and required more stents (2.2 ± 0.8 vs 1.2 ± 0.5, P = 0.001). FFR was lower (P = 0.0003) with CTO (0.45 ± 0.15) than controls (0.58 ± 0.17) prior to intervention but similar after PCI (CTO 0.91 ± 0.05 vs non-CTO 0.90 ± 0.08). All CTO patients demonstrated an ischemic FFR, even with severe regional dysfunction or well-developed collaterals. Resting ischemia was present in 78% (39/50) of CTO patients as evidenced by a resting Pd /Pa of <0.80. CONCLUSION: In symptomatic patients, a CTO, even with regional left ventricular impairment and/or excellent collateral development, reveals an ischemic zone. This ischemic zone can be normalized by PCI with outcomes appearing to be comparable to non-CTO patients.

Symptomatic right ventricular ischemia secondary to a critical stenosis in a nondominant right coronary artery.

Stable angina pectoris owing to isolated right ventricular ischemia from a critical stenosis in a nondominant right coronary artery is a rare entity and documentation of isolated right ventricular ischemia even rarer. We present a case of isolated right ventricular ischemia documented by fractional flow reserve (FFR) and resolution of symptoms after percutaneous coronary intervention.

Reversal of ischemia of donor artery myocardium after recanalization of a chronic total occlusion.

BACKGROUND: Case reports have shown that an intermediate stenosis in the donor artery collateralizing the myocardium of a chronic total occlusion (CTO) can produce an ischemic fractional flow reserve (FFR) value which may revert to non-ischemic with CTO revascularization. METHODS: A consecutive series of patients with severe angina in which a donor artery with intermediate stenosis (30-70%) had FFR measured before and after successful CTO recanalization were studied. RESULTS: Fourteen of 50 consecutive CTO patients with successful PCI fulfilled the study criteria. Eight had CTO of the right coronary artery (RCA), three circumflex (LCx), and three RCA and LCx. Left anterior descending artery was the donor artery in 13 and LCx in 1 patient. Of nine donor ischemic FFR patient's pre-PCI, six reverted to non-ischemic (FFR pre-PCI 0.76 ± 0.04 and 0.86 ± 0.03 post-PCI). Five patients had normal FFR in the donor artery pre- and post-CTO PCI. CONCLUSIONS: In patients with a CTO and an intermediate donor artery stenosis, the frequency of ischemia in the donor artery territory is relatively high and often normalized by successful CTO recanalization. These data recommend recanalizing the CTO first whenever possible as a preferred therapeutic strategy to avoid the need for PCI to the donor artery or multivessel bypass surgery.

Intentional Right Atrial Exit and Carbon Dioxide Insufflation to Facilitate Subxiphoid Needle Entry Into the Empty Pericardial Space: First Human Experience.

OBJECTIVES: The purpose of this study was to test whether a microcatheter can safely be advanced across the right atrial appendage to access the pericardium and then withdrawn despite subsequent high-intensity anticoagulation. We also tested whether transatrial pericardial insufflation of carbon dioxide (CO2) would enhance the safety of subxiphoid needle access to the empty pericardium by separating the heart from the anterior pericardium. BACKGROUND: Subxiphoid needle access to the empty pericardium, required for left atrial suture ligation and epicardial ablation for rhythm disorders, risks myocardial or coronary laceration. METHODS: A catheter from the femoral vein engaged the right atrial appendage for angiographic confirmation of position. Through that catheter, the back end of a 0.014- or 0.018-inch guidewire crossed the right atrial wall to enter the pericardium and delivered a 2.4-F microcatheter. CO2 1 to 2 ml/kg was insufflated into the pericardium immediately before subxiphoid needle access under lateral projection fluoroscopy. Thirteen patients undergoing subxiphoid suture ligation of the left atrial appendage consented to participate in this research protocol. RESULTS: Right atrial exit succeeded in 11 subjects (85%) and failed uneventfully in 2 subjects. CO2 insufflation of 96 ± 22 ml achieved 12 ± 4 mm separation of the anterior pericardium from the myocardial wall, allowed rapid and successful subxiphoid anterior needle and guidewire entry in all 11 subjects, and did not have any evident hemodynamic effects. The immediate pericardial aspirate was serous in all but 1 subject. CONCLUSIONS: We report the first human intentional transatrial exit procedure. Transatrial microcatheter access to the pericardium can be achieved safely. Pericardial insufflation with CO2 makes subxiphoid access to the empty pericardium rapid and safe. Although our clinical experience to date remains small, with further experience, this approach may prevent the life-threatening complications of "dry" subxiphoid pericardial access.