The field of interventional cardiology has significantly evolved over 40 years by overcoming several challenges. The introduction of first-generation drug-eluting stents significantly reduced the rates of restenosis, but at the expense of an increase of late stent thrombosis. Prolonged antithrombotic therapy reduced rates of stent thrombosis, but at the cost of increased bleeding. Although the advent of second-generation drug-eluting stents subsequently reduced the incidence of late stent thrombosis, its permanent nature prevents full recovery of vascular structure and function with accordant risk of very late stent failure. In the present era of interventional cardiology, the tradeoff between stent thrombosis, restenosis, and bleeding presents as a particularly complex challenge. In this review, the authors highlight major contributors of late/very late stent thrombosis while targeting stent restenosis, and they discuss evolutionary advances in stent technology and antiplatelet therapy, to further improve upon the care of patients with coronary artery disease.

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Carotid-femoral pulse wave velocity (PWV) has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American) population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV) disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender); asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n = 429) were categorized according to the age decade and the blood pressure levels (at study time). All subjects represented the “reference population”; the group of subjects with optimal/normal blood pressures levels at study time represented the “normal population.” Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes.

Introduction. An altered endothelial function (EF) could be associated with preeclampsia (PE). However, more specific and complementary analyses are required to confirm this topic. Flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and hyperemic-related changes in carotid-radial pulse wave velocity (PWVcr) offer complementary information about “recruitability” of EF. Objectives. To evaluate, in healthy and hypertensive pregnant women (with and without PE), central arterial parameters in conjunction with “basal and recruitable” EF. Methods. Nonhypertensive (HP) and hypertensive pregnant women (gestational hypertension, GH; preeclampsia, PE) were included. Aortic blood pressure (BP), wave reflection parameters (AIx@75), aortic pulse wave velocity (PWVcf) and PWVcr, and brachial and common carotid stiffness and intima-media thickness were measured. Brachial FMD and L-FMC and hyperemic-related change in PWVcr were measured. Results. Aortic BP and AIx@75 were elevated in PE. PE showed stiffer elastic but not muscular arteries. After cuff deflation, PWVcr decreased in HP, while GH showed a blunted PWVcr response and PE showed a tendency to increase. Maximal FMD and L-FMC were observed in HP followed by GH; PE did not reach significant arterial constriction. Conclusion. Aortic BP and wave reflections as well as elastic arteries stiffness are increased in PE. PE showed both “resting and recruitable” endothelial dysfunctions.

This work was carried out in a Uruguayan (South American) population to characterize aging-associated physiological arterial changes. Parameters markers of subclinical atherosclerosis and that associate age-related changes were evaluated in healthy people. A conservative approach was used and people with nonphysiological and pathological conditions were excluded. Then, we excluded subjects with (a) cardiovascular (CV) symptoms, (b) CV disease, (c) diabetes mellitus or renal failure, and (d) traditional CV risk factors (other than age and gender). Subjects (n = 388) were submitted to non-invasive vascular studies (gold-standard techniques), to evaluate (1) common (CCA), internal, and external carotid plaque prevalence, (2) CCA intima-media thickness and diameter, (3) CCA stiffness (percentual pulsatility, compliance, distensibility, and stiffness index), (4) aortic stiffness (carotid-femoral pulse wave velocity), and (5) peripheral and central pressure wave-derived parameters. Age groups: ≤20, 21–30, 31–40, 41–50, 51–60, 61–70, and 71–80 years old. Age-related structural and functional vascular parameters profiles were obtained and analyzed considering data from other populations. The work has the strength of being the first, in Latin America, that uses an integrative approach to characterize vascular aging-related changes. Data could be used to define vascular aging and abnormal or disease-related changes.

Donation after circulatory death donors (DCD) have the potential to increase the number of heart transplants. The DCD hearts undergo an extended period of warm ischemia, which mandates the use of machine perfusion preservation if they are to be successfully recovered for transplantation. Because the minimum coronary artery flow needed to meet the basal oxygen demand (DCRIT) of a DCD heart during machine perfusion preservation is critical and yet unknown, we studied this in a DCD rat heart model. Adult male rats were anesthetized, intubated, heparinized, and paralyzed with vecuronium. The DCD hearts (n = 9) were recovered 30 minutes after circulatory death whereas non-DCD control hearts (n = 12) were recovered without circulatory death. Hearts were perfused through the aorta with an oxygenated Belzer Modified Machine Perfusion Solution (A3-Bridge to Life Ltd. Columbia, SC) at 15°C or 22°C starting at a flow index of 300 ml/100 g/min and decreasing by 40 ml/100 g/min every 10 minutes. Inflow (aortic) and outflow (inferior vena cava) perfusate samples were collected serially to assess the myocardial oxygen consumption index (MVO2) and O2 extraction ratio. The DCRIT is the minimum coronary flow below which the MVO2 becomes flow dependent. The MVO2, DCRIT, and oxygen extraction ratios were higher in DCD hearts compared with control hearts. The DCRIT for DCD hearts was achieved only at 15°C and was significantly higher (131.6 ± 7 ml/100 g/min) compared with control hearts (107.7 ± 8.4 ml/100 gm/min). The DCD hearts sustain warm ischemic damage and manifest higher metabolic needs during machine perfusion. Establishing adequate coronary perfusion is critical to preserving organ function for potential heart transplantation.

Preeclampsia is a worldwide pregnancy complication with serious short and long-term maternal and neonatal consequences. Our understanding of preeclampsia pathophysiology has significantly evolved over the last decades with the recognition that impaired arterial function and structure may occur early in the course of pregnancy, preceding the clinic-humoral syndrome and driving long-term cardiovascular disease risk in the future of these patients. Although an early abnormal placentation may be the inciting event for a large proportion of cases, there is growing evidence that challenges the placental hypothesis in all affected women, since placental histopathology lesions thought to be characteristic are neither sensitive nor specific markers for the disorder. Recent hemodynamic investigations and studies on left ventricular function and structure in women with preeclampsia further challenge this universal paradigm and propose that placental dysfunction could be secondary to a maternal cardiovascular maladaptation to pregnancy in certain patients. Supporting this hypothesis, certain vascular features, which are characteristically enhanced in normal pregnancy allowing a healthy vascular adaptation are absent in preeclampsia and comparable to the non-pregnant population. However, arterial biomechanics in preeclampsia may only not cope with hemodynamic demands of pregnancy, but also impose additional detrimental loads to the maternal heart ("impaired left-ventricle-aorta coupling") and transmit pressure and flow disturbances into the fetoplacental circulation ("impaired large arteries-microcirculation coupling"). In this review, we analyze the major role of the arterial dysfunction in the cardiovascular maladaptation hypothesis of preeclampsia, shed light on its potential etiopathogenic link and discuss the complementary nature of the placental and cardiovascular theories.

Background Tachycardia and heart rate irregularity are proposed triggers of premature ventricular contraction–induced cardiomyopathy (PVC-cardiomyopathy). Bigeminal premature atrial and ventricular contractions (PACs and PVCs) increase heart rate and result in rhythm irregularities but differ in their effects on ventricular synchrony. Comparing chronic bigeminal PACs with PVCs would provide insights into mechanisms of PVC-cardiomyopathy. Objective To compare the impact of chronic PACs and PVCs on ventricular hemodynamics, structure, and function. Methods Pacemakers were implanted in 27 canines to reproduce atrial (PACs, n = 7) or ventricular bigeminy (PVCs, n = 11) for 12 weeks, and compared to sham-operated animals (n = 9). Four additional animals were exposed to long-term bigeminal PVCs (48 weeks). Hemodynamic changes were assessed using a pressure-transducing catheter at baseline and 12 weeks. Cardiac remodeling was monitored by transthoracic echocardiography throughout the 12- and 48-week protocols in the respective groups. Results PVC group demonstrated a significant decrease in left ventricular (LV) ejection fraction and contractility (max dP/dt), impaired LV lusitropy (min dP/dt), and increase in LV dimensions and LV mass at 12 weeks without further deterioration beyond 16 weeks. Despite increased LV mass, relative wall thickness decreased, consistent with eccentric hypertrophy. No significant cardiac remodeling was noted in either sham or PAC groups at 12 weeks. Conclusion In contrast to bigeminal PACs, PVCs result in a cardiomyopathy characterized by reduced LV ejection fraction, LV dilation, and eccentric hypertrophy that plateaus between 12 and 16 weeks. The lack of remodeling in chronic PACs suggests that tachycardia and heart rate irregularity do not play a significant role on the development of PVC-cardiomyopathy.