Safety Window for Effective Lesion Crossing in Patients With Chronic Thromboembolic Pulmonary Hypertension.

Background: Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension (CTEPH) is limited by a lack of safe and effective tools for crossing these lesions. We aim to identify a safety window for an intraluminal crossing device in this vascular bed by studying the piercing properties of pulmonary arterial vessel walls and intraluminal CTEPH lesion specimens. As a secondary objective, we also describe the histopathologic features of CTEPH lesions. Methods: Specimens were procured from 9 patients undergoing pulmonary endarterectomy. The specimens were subsampled and identified grossly as arterial wall or intraluminal CTEPH lesions. The force needed for tissue penetration was measured using a 0.38-mm (0.015-in) diameter probe in an ex vivo experimental model developed in our lab. Concurrent histology was also performed. Results: The mean force needed to penetrate the arterial wall and intraluminal CTEPH lesions was 1.75 ± 0.10 N (n = 121) and 0.30 ± 0.04 N (n = 56), respectively (P < .001). Histology confirmed the presence of intimal hyperplasia with calcium and hemosiderin deposition in the arterial wall as well as an old, organized thrombus in the lumen. Conclusions: The pulmonary arterial wall is friable and prone to perforation during instrumentation with workhorse coronary guide wires. However, the results of this study demonstrate that a much lower force is needed for the 0.38-mm (0.015-in) probe to penetrate an intraluminal CTEPH lesion compared to pulmonary arterial intima. This finding suggests the existence of a safety window for lesion-crossing devices, enabling effective balloon pulmonary angioplasty.

Long-term outcomes and predictors of mortality in patients with pulmonary embolism undergoing catheter-directed thrombolysis: a 10-year retrospective study.

BACKGROUND: Data regarding long-term outcomes of catheter-directed thrombolysis (CDT) post intermediate risk pulmonary embolism (PE), the choice of anticoagulation, and factors affecting mortality are not well studied. METHODS: We conducted a ten-year retrospective observational chart review of patients undergoing CDT for intermediate-risk PE. Patients were followed for a period of 1 to a maximum of 5 years from the PE event. Multivariate regression analysis was used to identify independent predictors of mortality post-CDT. RESULTS: We had a total of 373 patients in our study. Significant 5-year mortality was observed (18.7 %) in our patient population, with a 9.2 % cardiopulmonary cause of death. Rate was highest in patients without anticoagulation (78.5 %) and least in patients on apixaban [10.9 %, absolute risk reduction - 63.8 % (40.91 % - 86.60 %)]. Age, female sex and no anticoagulation were independently associated with mortality. CONCLUSION: CDT for intermediate-risk PE has a high 5-year mortality with no anticoagulation as the only modifiable risk factor.

Mechanical activation of noncoding-RNA-mediated regulation of disease-associated phenotypes in human cardiomyocytes.

How common polymorphisms in noncoding genome regions can regulate cellular function remains largely unknown. Here we show that cardiac fibrosis, mimicked using a hydrogel with controllable stiffness, affects the regulation of the phenotypes of human cardiomyocytes by a portion of the long noncoding RNA ANRIL, the gene of which is located in the disease-associated 9p21 locus. In a physiological environment, cultured cardiomyocytes derived from induced pluripotent stem cells obtained from patients who are homozygous for cardiovascular-risk alleles (R/R cardiomyocytes) or from healthy individuals who are homozygous for nonrisk alleles contracted synchronously, independently of genotype. After hydrogel stiffening to mimic fibrosis, only the R/R cardiomyocytes exhibited asynchronous contractions. These effects were associated with increased expression of the short ANRIL isoform in R/R cardiomyocytes, which induced a c-Jun N-terminal kinase (JNK) phosphorylation-based mechanism that impaired gap junctions (particularly, loss of connexin-43 expression) following stiffening. Deletion of the risk locus or treatment with a JNK antagonist was sufficient to maintain gap junctions and prevent asynchronous contraction of cardiomyocytes. Our findings suggest that mechanical changes in the microenvironment of cardiomyocytes can activate the regulation of their function by noncoding loci.