Technical Considerations and Practical Guidance for Intracoronary Optical Coherence Tomography.

Optical coherence tomography (OCT) is an intravascular imaging technology analogous to intravascular ultrasound, using near-infrared light rather than ultrasound, thereby providing higher-resolution images. This review provides a practical guide to OCT imaging, with a particular emphasis on the techniques and approaches to optimize image acquisition, improve the evaluation of coronary lesions, and guide the strategies for percutaneous coronary intervention.

Late gadolinium enhancement on cardiac magnetic resonance predicts adverse cardiovascular outcomes in nonischemic cardiomyopathy: a systematic review and meta-analysis.

BACKGROUND: Late gadolinium enhancement (LGE) by cardiac MR (CMR) is a predictor of adverse cardiovascular outcomes in patients with nonischemic cardiomyopathy (NICM). However, these findings are limited by single-center studies, small sample sizes, and low event rates. We performed a meta-analysis to evaluate the prognostic role of LGE by CMR (LGE-CMR) imaging in patients with NICM. METHODS AND RESULTS: PubMed, Cochrane CENTRAL, and EMBASE were searched for studies looking at the prognostic value of LGE-CMR in patients with NICM. The primary end points included all-cause mortality, heart failure hospitalization, and a composite end point of sudden cardiac death (SCD) or aborted SCD. Pooling of odds ratios was performed using a random-effect model, and annualized event rates were assessed. Data were included from 9 studies with a total of 1488 patients and a mean follow-up of 30 months. Patients had a mean age of 52 years, 67% were men, and the average left ventricular ejection fraction was 37% on CMR. LGE was present in 38% of patients. Patients with LGE had increased overall mortality (odds ratio, 3.27; P<0.00001), heart failure hospitalization (odds ratio, 2.91; P=0.02), and SCD/aborted SCD (odds ratio, 5.32; P<0.00001) compared with those without LGE. The annualized event rates for mortality were 4.7% for LGE+ subjects versus 1.7% for LGE- subjects (P=0.01), 5.03% versus 1.8% for heart failure hospitalization (P=0.002), and 6.0% versus 1.2% for SCD/aborted SCD (P<0.001). CONCLUSIONS: LGE in patients with NICM is associated with increased risk of all-cause mortality, heart failure hospitalization, and SCD. Detection of LGE by CMR has excellent prognostic characteristics and may help guide risk stratification and management in patients with NICM.

Adeno-associated virus serotype 9-mediated overexpression of extracellular superoxide dismutase improves recovery from surgical hind-limb ischemia in BALB/c mice.

OBJECTIVE: Neovascularization is a physiologic repair process that partly depends on nitric oxide. Extracellular superoxide dismutase (EcSOD) is the major scavenger of superoxide. It is an important regulator of nitric oxide bioavailability and thus protects against vascular dysfunction. We hypothesized that overexpression of EcSOD in skeletal muscle would improve recovery from hind-limb ischemia. METHODS: Adeno-associated virus serotype 9 (AAV9) vectors expressing EcSOD or luciferase (control) from the cytomegalovirus promoter were cross-packaged into AAV9 capsids and injected intramuscularly into the hind-limb muscles (1 × 10(11) viral genomes/limb) of 12-week-old mice. Ischemia was induced after intramuscular injections. Laser Doppler was used to measure limb perfusion on days 0, 7, and 14 after injection. Values were expressed as a ratio relative to the nonischemic limb. EcSOD expression was measured by Western blotting. Capillary density was documented by immunohistochemical staining for platelet endothelial cell adhesion molecule. Apoptosis was assessed by terminal deoxynucleotide transferase-mediated biotin-deoxy uridine triphosphate nick-end labeling and necrosis was visually evaluated daily. RESULTS: EcSOD expression was twofold upregulated in EcSOD treated vs control ischemic muscles at day 14. Capillary density (capillaries/fiber) was 1.9-fold higher in treated (1.65 ± 0.02) vs control muscle (0.78 ± 0.17, P < .05). Recovery of perfusion ratio at day 14 after ischemia was 1.5-fold greater in EcSOD vs control mice (P < .05). The percentage of apoptotic nuclei was 1.3% ± 0.4% in EcSOD-treated mice compared with 4.2% ± 0.2% in controls (P < .001). Limb necrosis was also significantly lower in EcSOD vs control mice. CONCLUSION: AAV9-mediated overexpression of EcSOD in skeletal muscle significantly improves recovery from hind-limb ischemia in mice, consistent with improved capillary density and perfusion ratios in treated mice.

Peripheral arterial disease in diabetes: is there a role for genetics?

Atherosclerotic occlusion of vessels outside of the heart is commonly referred to as peripheral arterial disease (PAD). The lower extremity is the most common site of PAD and its development is associated with the same risk factors involved in general atherosclerosis. However, there is emerging evidence that other risk factors may play a key role in the development of PAD. Over the past decade polymorphism in a number of genes has been shown to contribute to the risk of developing PAD. These genes can be classified into proartherosclerosis or proatherothrombosis based on the known gene function. Moreover, they can be categorized as "novel" polymorphism when the function of the genes is not known or when the specific gene within an associated genetic locus is not known. It is intriguing that not only are gene polymorphisms associated with PAD being identified, but more recently studies are now finding gene polymorphisms that may be important in development of this syndrome only in the contest of certain environmental factors such as diabetes. Currently how these gene-environment interactions contribute to the pathogenesis of PAD is poorly understood but will likely play a critical role in future understanding of this complex disease.

Rotational vertebrobasilar ischemia due to vertebral artery dynamic stenoses complicated by an ostial atherosclerotic stenosis.

We describe a patient with rotational vertebrobasilar ischemia (RVBI) due to vertebral artery (VA) compressive stenoses during neck rotation, complicated by an ostial atherosclerotic stenosis (OAS). Referred for 'near-syncopal spells', inquiry revealed a symptom-complex consistent with vertebrobasilar transient ischemic attacks (TIAs) provoked by head rotation. VA dynamic angiography with imaging via prevertebral subclavian injections in neck-rotated positions while reproducing symptoms, demonstrated two compressive stenoses not present in the neck-neutral position, establishing the diagnosis of RVBI due to CT-demonstrated cervical spondylosis. There was an occluded contralateral VA, isolated posterior circulation, and absent vertebral collateral flow. Disabling symptoms persisted despite using a cervical collar. Surgical decompression of the dynamic stenoses would not address the OAS, was considered high risk, and absence of a suitable donor artery precluded distal VA reconstruction. RVBI resolved with ostial stent placement by improving perfusion pressure across the compressive stenoses. To our knowledge, this is the first report of RVBI in which the affected VA had an obstructive atherosclerotic stenosis in addition to the characteristic rotation-induced dynamic stenoses, and the first report of stent placement in the culprit artery to treat this disorder. Diagnosis depends on recognizing the association of symptoms with positional neck changes and VA dynamic angiography demonstrating the compressive stenosis while reproducing symptoms. This case illustrates the management complexities when there are coexisting abnormalities, emphasizing the need to individualize treatment. RVBI is a potentially correctable cause of TIAs and particularly relevant due to the aging population which has a significant incidence of both degenerative cervical and atherosclerotic cerebrovascular disease.

Use of a wireless implantable cardioverter defibrillator in a patient with a preexisting neurostimulator.

We report the case of a 54-year-old man with a previously implanted neurostimulator who presented with palpitations and was found to have sustained ventricular tachycardia on electrophysiologic study. A Medtronic wireless implantable cardioverter defibrillator (ICD; Medtronic Inc., Minneapolis, MN, USA) with home monitoring (HM) was successfully implanted. Interaction testing during implantation, follow-up, and HM showed that there was no device-device interaction.