Restenosis rates for drug-eluting stents used in treating small vessel cardiac allograft vasculopathy after orthotopic heart transplantation.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is associated with increased mortality in patients with orthotopic heart transplantation (OHT). In addition to immunosuppression, CAV can be treated with percutaneous coronary intervention (PCI) with drug eluting stents (DES) for focal lesions. There is a paucity of data on the rate of DES restenosis in patients with small vessel CAV. METHODS: This was a retrospective observational study of 101 coronary vessels treated with a DES diameter of 2.5 mm or less (small vessels) in 61 OHT patients compared to 72 coronary vessels treated with a DES diameter of >2.5 mm (large vessels) in 44 OHT patients at a single center between 2004 and 2022. Baseline demographic data, angiographic characteristics, and clinical outcomes were analyzed. RESULTS: At an average of 1.6 years after DES placement, follow-up angiography revealed in-stent restenosis in 36 (39 %) small vessel interventions and 11 (17 %) large vessel interventions (p = 0.003). Long term mortality did not differ between the groups (59 % vs 59 % at a median of 4.7 [IQR 2.4-7.8] years follow up). CONCLUSION: DES restenosis rates are high in small vessel CAV. Additional studies specifically examining PCI in small vessel CAV as well as the potential role for newer treatment strategies for CAV are warranted.

Circulating Progenitor Cells and Coronary Collaterals in Chronic Total Occlusion.

BACKGROUND: The role of circulating progenitor cells (CPC) in collateral formation that occurs in the presence of chronic total occlusions (CTO) of a coronary artery is not well established. In stable patients with a CTO, we investigated whether CPC levels are associated with (a) collateral development and (b) ischemic burden, as measured by circulating high sensitivity troponin-I (hsTn-I) levels. METHODS: CPCs were enumerated by flow cytometry as CD45med+ blood mononuclear cells expressing CD34 and both CD34 and CD133 epitopes. The association between CPC counts and both Rentrop collateral grade (0, 1, 2, or 3) and hsTn-I levels were evaluated using multivariate regression analysis, after adjusting for demographic and clinical characteristics. RESULTS: In 89 patients (age 65.5, 72% male, 27% Black), a higher CPC count was positively associated with a higher Rentrop collateral grade; [CD34+ adjusted odds ratio (OR) 1.49 95% confidence interval (CI) (0.95, 2.34) P = 0.082] and [CD34+/CD133+ OR 1.57 95% CI (1.05, 2.36) P = 0.028]. Every doubling of CPC counts was also associated with lower hsTn-I levels [CD34+ ß -0.35 95% CI (-0.49, -0.15) P = 0.002] and [CD34+/CD133+ ß -0.27 95% CI (-0.43, -0.08) P = 0.009] after adjustment. CONCLUSION: Individuals with higher CPC counts have greater collateral development and lower ischemic burden in the presence of a CTO.

Intravascular lithotripsy compared to rotational atherectomy for the treatment of calcified distal left main coronary artery disease: A single center experience.

BACKGROUND: The safety and efficacy of intravascular lithotripsy (IVL) for the treatment of calcified distal left main (LM) disease remains unclear, especially compared to rotational atherectomy (RA). METHODS: We retrospectively analyzed the baseline clinical, angiographic, intravascular ultrasound (IVUS) characteristics and procedural outcomes of 107 patients who underwent distal LM percutaneous coronary intervention (PCI) with IVL (with or without adjunct atherectomy) versus RA alone for plaque modification before stenting at a single center between 2020 and 2022. RESULTS: A total of 50 patients underwent calcium modification with IVL with or without adjunct atherectomy and 57 with RA only. The mean age was 73 years and with a high prevalence of diabetes (58.9%), chronic kidney disease (42.1%), prior revascularization (coronary artery bypass graft surgery [36.4%] or prior PCI [32.7%]). Acute coronary syndrome was the primary indication for PCI in over 50% of the patients in both groups. Medina 1-1-1 LM bifurcation disease was identified in 64% and 60% of the IVL and RA groups (p = 0.64) respectively. Final minimum stent area in distal LM (>8.2 mm2 ), ostial LAD (>6.3 mm2 ) and ostial LCX (>5.0 mm2 ) were achieved in 96%, 85% and 89% of cases treated with IVL respectively and 93%, 93% and 100% of cases treated with RA respectively (LM p = 1.00; LAD p = 0.62; LCX; p = 1.00 for difference between the two groups). Procedural success (technical success without in-hospital major adverse events) was achieved in 98% of the IVL group and 86% of the RA-only group (p = 0.04). There were eight procedural complications (flow-limiting dissection, perforation, or slow/no-reflow) in the RA group compared to four in the IVL group (NS), and one patient in the RA required salvaged mechanical support compared to none in the IVL group. CONCLUSION: Plaque modification with coronary IVL appears to be efficacious and safe for the treatment of severely calcified distal LM lesions compared to RA only. Larger randomized studies are needed to confirm these findings.

HDL: Fact, fiction, or function? HDL cholesterol and cardiovascular risk.

The measurement of high-density lipoprotein cholesterol is highly utilized by clinicians to help predict cardiovascular risk, but this measure is not causally associated with atherosclerotic cardiovascular disease events. The use of Mendelian randomization studies has led to a change in investigative attention from the high-density lipoprotein cholesterol concentration to its physiological functions. High-density lipoprotein plays key roles in important pathways related to the development of atherosclerotic disease including reverse cholesterol transport, oxidation and inflammation, and endothelial function as well as in other physiological systems including immune system modulation, cellular apoptosis, and endothelial progenitor cell homeostasis. The identification of dysfunctional high-density lipoprotein may better predict future cardiovascular events compared to numerical high-density lipoprotein cholesterol and aid in enhanced clinical risk stratification. The emergence of discrete physiological measurements of high-density lipoprotein, such as cholesterol efflux capacity and the high-density lipoprotein inflammatory index, may provide an opportunity for clinical application in the future. However, the validity of these measurements and their commercial availability remain barriers to a realistic transition to clinical medicine.

Use of High-Sensitivity Cardiac Troponin for the Exclusion of Inducible Myocardial Ischemia: A Cohort Study.

Background: Many patients with coronary artery disease (CAD) are routinely referred for surveillance stress testing despite recommendations against it. Objective: To determine whether low levels of resting high-sensitivity cardiac troponin I (hs-cTnI) can identify persons without inducible myocardial ischemia. Design: Observational study. Setting: A university-affiliated hospital network. Patients: Persons with stable CAD: 589 in the derivation group and 118 in the validation cohort. Measurements: Presence of inducible myocardial ischemia was determined by myocardial perfusion imaging with technetium-99m single-photon emission computed tomography during either treadmill or pharmacologic stress testing. Resting plasma hs-cTnI was measured within 1 week of the stress test, and the negative predictive value (NPV) for inducible ischemia was calculated. The derivation cohort was followed for 3 years for incident cardiovascular death and myocardial infarction. Results: In the derivation cohort, 10 of 101 patients with an hs-cTnI level below 2.5 pg/mL had inducible myocardial ischemia (NPV, 90% [95% CI, 83% to 95%]) and 3 of 101 had inducible ischemia involving at least 10% of the myocardium (NPV, 97% [CI, 92% to 99%]). In the validation cohort, 4 of 32 patients with an hs-cTnI level below 2.5 pg/mL had inducible ischemia (NPV, 88% [CI, 71% to 96%]) and 2 of 32 had ischemia of 10% or greater (NPV, 94% [CI, 79% to 99%]). After a median follow-up of 3 years in the derivation cohort, no adverse events occurred in patients with an hs-cTnI level below 2.5 pg/mL, compared with 33 (7%) cardiovascular deaths or incident myocardial infarctions among those with an hs-cTnI level of 2.5 pg/mL or greater. Limitation: The data may not be applicable to a population without known CAD or to persons with unstable angina, and the modest sample sizes warrant further validation in a larger cohort. Conclusion: Very low hs-cTnI levels may be useful in excluding inducible myocardial ischemia in patients with stable CAD. Primary Funding Source: National Institutes of Health.

Degenerative mitral regurgitation predicts worse outcomes in patients undergoing transcatheter aortic valve replacement.

OBJECTIVES: To evaluate the role mitral regurgitation (MR) etiology and severity play in outcomes for patients undergoing transcatheter aortic valve replacement (TAVR). BACKGROUND: Multiple prior studies have investigated the influence of MR severity on outcomes for patients undergoing TAVR. Less has been published regarding the effects of MR etiology on outcomes, including its impact on heart failure hospitalization. METHODS: Two hundred and seventy patients undergoing TAVR at 2 hospitals were enrolled. Each patient had a baseline and follow-up (within 30 days of TAVR) echocardiogram that was analyzed. MR was graded as none, mild, moderate, or severe, as well as functional or degenerative. We compared patient outcomes, including death and heart failure hospitalization, among none-mild MR, moderate-severe functional MR, and moderate-severe degenerative MR groups. RESULTS: Two hundred and seventy patients underwent TAVR, reducing mean aortic valve gradients from 45 ± 15 mm Hg to 9 ± 4 mm Hg. On multivariable analysis, only patients with moderate-severe degenerative MR had decreased survival free of death or CHF hospitalization compared to those with none-mild MR (P = .011). Subanalysis showed patients with moderate-severe degenerative MR were more likely to be hospitalized for heart failure at 2 years compared to those with moderate-severe functional MR (P = .02). Patients with moderate-severe degenerative MR were also less likely to have improvement in MR severity at follow up (P = .01). CONCLUSIONS: Special consideration should be given to patients with moderate-severe degenerative MR undergoing TAVR. As transcatheter approaches for mitral valve repair and replacement continue to evolve, moderate-severe degenerative MR patients may benefit from consideration of double valve intervention.

Myocardial Ischemia and Mobilization of Circulating Progenitor Cells.

BackgroundThe response of progenitor cells (PCs) to transient myocardial ischemia in patients with coronary artery disease remains unknown. We aimed to investigate the PC response to exercise-induced myocardial ischemia (ExMI) and compare it to flow mismatch during pharmacological stress testing. Methods and ResultsA total of 356 patients with stable coronary artery disease underwent 99mTc-sestamibi myocardial perfusion imaging during exercise (69%) or pharmacological stress (31%). CD34+ and CD34+/chemokine (C-X-C motif) receptor 4 PCs were enumerated by flow cytometry. Change in PC count was compared between patients with and without myocardial ischemia using linear regression models. Vascular endothelial growth factor and stromal-derived factor-1α were quantified. Mean age was 63±9 years; 76% were men. The incidence of ExMI was 31% and 41% during exercise and pharmacological stress testing, respectively. Patients with ExMI had a significant decrease in CD34+/chemokine (C-X-C motif) receptor 4 (-18%, P=0.01) after stress that was inversely correlated with the magnitude of ischemia (r=-0.19, P=0.003). In contrast, patients without ExMI had an increase in CD34+/chemokine (C-X-C motif) receptor 4 (14.7%, P=0.02), and those undergoing pharmacological stress had no change. Plasma vascular endothelial growth factor levels increased (15%, P<0.001) in all patients undergoing exercise stress testing regardless of ischemia. However, the change in stromal-derived factor-1α level correlated inversely with the change in PC counts in those with ExMI (P=0.03), suggesting a greater decrease in PCs in those with a greater change in stromal-derived factor-1α level with exercise. ConclusionsExMI is associated with a significant decrease in circulating levels of CD34+/chemokine (C-X-C motif) receptor 4 PCs, likely attributable, at least in part, to stromal-derived factor-1α-mediated homing of PCs to the ischemic myocardium. The physiologic consequences of this uptake of PCs and their therapeutic implications need further investigation.

Navigating air travel and cardiovascular concerns: Is the sky the limit?

As the population ages and our ability to care for patients with cardiac disease improves, an increasing number of passengers with cardiovascular conditions will be traveling long distances. Many have had cardiac symptoms, recent interventions, devices, or surgery. Air travel is safe for most individuals with stable cardiovascular disease. However, a thorough understanding of the physiologic changes during air travel is essential given the potential impact on cardiovascular health and the risk of complications in passengers with preexisting cardiac conditions. It is important for clinicians to be aware of the current recommendations and precautions that need to be taken before and during air travel for passengers with cardiovascular concerns.