Coronary wave intensity patterns in stable coronary artery disease: influence of stenosis severity and collateral circulation.

Objective: Wave intensity analysis is a method that allows separating pulse waves into components generated proximally and in the periphery of arterial trees, as well as characterising them as accelerating or decelerating. The early diastolic suction wave (eaDSW) is one of the most prominent wave events in the coronaries. The aim of this study was to determine whether (1) microvascular dilatation directly influences its energy, (2) stenosis severity can be assessed proximal to stenoses, (3) distal pulse wave entrapment exists in the presence of stenoses and (4) coronary collaterals influence wave entrapment.

Time-Dependent Myocardial Necrosis in Patients With ST-Segment-Elevation Myocardial Infarction Without Angiographic Collateral Flow Visualized by Cardiac Magnetic Resonance Imaging: Results From the Multicenter STEMI-SCAR Project.

Background Acute complete occlusion of a coronary artery results in progressive ischemia, moving from the endocardium to the epicardium (ie, wavefront). Dependent on time to reperfusion and collateral flow, myocardial infarction ( MI ) will manifest, with transmural MI portending poor prognosis. Late gadolinium enhancement cardiac magnetic resonance imaging can detect MI with  high diagnostic accuracy.

The effect of pegylated granulocyte colony-stimulating factor on collateral function and myocardial ischaemia in chronic coronary artery disease: A randomized controlled trial.

Objective: To test the effect of long-term pegfilgrastim on collateral function and myocardial ischaemia in patients with chronic stable coronary artery disease (CAD).

Methods: This was a prospective clinical trial with randomized 2:1 allocation to pegfilgrastim or placebo for 6 months. The primary study endpoint was collateral flow index (CFI) as obtained during a 1-minute ostial coronary artery balloon occlusion.

Selective Heart Rate Reduction With Ivabradine Increases Central Blood Pressure in Stable Coronary Artery Disease.

Heart rate (HR) lowering by β-blockade was shown to be beneficial after myocardial infarction. In contrast, HR lowering with ivabradine was found to confer no benefits in 2 prospective randomized trials in patients with coronary artery disease. We hypothesized that this inefficacy could be in part related to ivabradine's effect on central (aortic) pressure.

Effects of Thoratec pulsatile ventricular assist device timing on the abdominal aortic wave intensity pattern.

Arterial waves are seen as possible independent mediators of cardiovascular risks, and the wave intensity analysis (WIA) has therefore been proposed as a method for patient selection for ventricular assist device (VAD) implantation. Interpreting measured wave intensity (WI) is challenging, and complexity is increased by the implantation of a VAD. The waves generated by the VAD interact with the waves generated by the native heart, and this interaction varies with changing VAD settings.

Electrocardiographic ST-segment monitoring during controlled occlusion of coronary arteries.

Background: Ischemia monitoring cannot always be performed by 12-lead ECG. Hence, the individual performance of the ECG leads is crucial. No experimental data on the ECG's specificity for transient ischemia exist.

The effect of heart rate reduction by ivabradine on collateral function in patients with chronic stable coronary artery disease.

Objective: To evaluate the effect of heart rate reduction by ivabradine on coronary collateral function in patients with chronic stable coronary artery disease (CAD).

Methods: This was a prospective randomised placebo-controlled monocentre trial in a university hospital setting. 46 patients with chronic stable CAD received placebo (n=23) or ivabradine (n=23) for the duration of 6 months.

Prognostic relevance of coronary collateral function: confounded or causal relationship?

Objective: To expand the limited information on the prognostic impact of quantitatively obtained collateral function in patients with coronary artery disease (CAD) and to estimate causality of such a relation.

Design: Prospective cohort study with long-term observation of clinical outcome.

Setting: University Hospital.

Direct quantitative assessment of the peripheral artery collateral circulation in patients undergoing angiography.

Background: Despite the fact that numerous studies have pursued the strategy of improving collateral function in patients with peripheral artery disease, there is currently no method available to quantify collateral arterial function of the lower limb.

Methods And Results: Pressure-derived collateral flow index (CFIp, calculated as (occlusive pressure-central venous pressure)/(aortic pressure-central venous pressure); pressure values in mm Hg) of the left superficial femoral artery was obtained in patients undergoing elective coronary angiography using a combined pressure/Doppler wire (n=30). Distal occlusive pressure and toe oxygen saturation (Sao2) were measured for 5 minutes under resting conditions, followed by an exercise protocol (repetitive plantar-flexion movements in supine position; n=28).

Quantitative myocardial contrast echocardiography: a new method for the non-invasive detection of chronic heart transplant rejection.

Background: Chronic heart transplant rejection, i.e. cardiac allograft vasculopathy (CAV) is a major adverse prognostic factor after heart transplantation (HTx).

G-CSF induced arteriogenesis in humans: molecular insights into a randomized controlled trial.

Aims: Recent data have demonstrated the feasibility of therapeutic induction of coronary collateral growth (arteriogenesis); however, mechanisms of action of such therapeutic collateral stimulation in humans are unknown. The aim of this study was to evaluate potential mechanisms, especially the involvement of arteriogenesis-relevant genes.

Methods And Results: A total of 52 patients were randomized into two groups: subcutaneous G-CSF (10 μg/kg; n=26) or placebo (n=26).

Effects of coronary sinus occlusion on myocardial ischaemia in humans: role of coronary collateral function.

Objective: This study tested the hypotheses that intermittent coronary sinus occlusion (iCSO) reduces myocardial ischaemia, and that the amount of ischaemia reduction is related to coronary collateral function.

Design: Prospective case-control study with intraindividual comparison of myocardial ischaemia during two 2-min coronary artery balloon occlusions with and without simultaneous iCSO by a balloon-tipped catheter.

Setting: University Hospital.

Cause or effect of arteriogenesis: compositional alterations of microparticles from CAD patients undergoing external counterpulsation therapy.

Unlabelled: Recently, a clinical study on patients with stable coronary artery disease (CAD) showed that external counterpulsation therapy (ECP) at high (300 mmHg) but not at low inflation pressure (80 mmHg) promoted coronary collateral growth, most likely due to shear stress-induced arteriogenesis. The exact molecular mechanisms behind shear stress-induced arteriogenesis are still obscure. We therefore characterized plasma levels of circulating microparticles (MPs) from these CAD patients because of their ambivalent nature as a known cardiovascular risk factor and as a promoter of neovascularization in the case of platelet-derived MPs.

Determinants of prognostically relevant intracoronary electrocardiogram ST-segment shift during coronary balloon occlusion.

The prognostic relevance of quantitative an intracoronary occlusive electrocardiographic (ECG) ST-segment shift and its determinants have not been investigated in humans. In 765 patients with chronic stable coronary artery disease, the following simultaneous quantitative measurements were obtained during a 1-minute coronary balloon occlusion: intracoronary ECG ST-segment shift (recorded by angioplasty guidewire), mean aortic pressure, mean distal coronary pressure, and mean central venous pressure (CVP). Collateral flow index (CFI) was calculated as follows: (mean distal coronary pressure minus CVP)/(mean aortic pressure minus CVP).

Coronary collaterals and risk for restenosis after percutaneous coronary interventions: a meta-analysis.

Background: The benefit of the coronary collateral circulation (natural bypass network) on survival is well established. However, data derived from smaller studies indicates that coronary collaterals may increase the risk for restenosis after percutaneous coronary interventions. The purpose of this systematic review and meta-analysis of observational studies was to explore the impact of the collateral circulation on the risk for restenosis.

Survival benefits of revascularization in patients with critical limb ischemia and renal insufficiency.

Background: Evidence for the best treatment strategy for patients with critical limb ischemia (CLI) at different stages of renal insufficiency (RI) is rare. Therefore, we determined the benefit of revascularization vs medical therapy (MT) only in CLI patients with different levels of RI.

Methods: This intention-to-treat cohort study with follow-up at 2, 6, and 12 months was conducted in a consecutive series of 351 patients with CLI.

Gender is an independent risk factor for distribution pattern and lesion morphology in chronic critical limb ischemia.

Background: The aim of this study was to determine gender differences in atherosclerotic lesion morphology and distribution pattern of patients with critical limb ischemia (CLI).

Methods: In this prospective cohort study, 233 patients, including 134 men (58%) and 99 women (43%) presenting with critically ischemic limbs were consecutively enrolled. Lesions of the entire lower limb arterial tree were evaluated and grouped into iliac, femoropopliteal, and below-the-knee (BTK) arterial disease.

Benefit of immediate revascularization in women with critical limb ischemia in an intention-to-treat analysis.

Background: Evidence for the best treatment strategy in women with critical limb ischemia (CLI) is limited and controversial with studies contradicting each other. Therefore, we determined the benefit of immediate revascularization compared to medical therapy (MT) with optional delayed revascularization in men and women with CLI.

Methods: This cohort study with follow-up at 2, 6, and 12 months was conducted in a consecutive series of 356 patients (41% women) presenting with 394 critically ischemic limbs.

Oversizing and restenosis with self-expanding stents in iliofemoral arteries.

Purpose: Uncoated self-expanding nitinol stents (NS) are commonly oversized in peripheral arteries. In current practice, 1-mm oversizing is recommended. Yet, oversizing of NS may be associated with increased restenosis.

Determinants of preformed collateral vessels in the human heart without coronary artery disease.

Background: Coronary collaterals protect myocardium jeopardized by coronary artery disease (CAD). Promotion of collateral circulation is desirable before myocardial damage occurs. Therefore, determinants of collateral preformation in patients without CAD should be elucidated.

Physical coronary arteriogenesis: a human "model" of collateral growth promotion.

In patients with coronary artery disease, the size of myocardial infarction mainly determines the subsequent clinical outcome. Accordingly, it is the primary strategy to decrease cardiovascular mortality by minimizing infarct size. Promotion of collateral artery growth (arteriogenesis) is an appealing option of reducing infarct size.

Coronary collateral function in the transplanted heart: propensity score matching with coronary artery disease.

Background: The function of the coronary collateral circulation in heart transplant patients has not been investigated in a controlled fashion. Since it partly belongs to the microcirculation, which is affected by transplant vasculopathy, the hypothesis was tested that the coronary collateral circulation in heart transplant recipients is less developed than in coronary artery disease (CAD) patients.

Methods: 40 heart transplant patients underwent a total of 51 quantitative, coronary pressure-derived collateral measurements and intravascular ultrasound (IVUS).

Estrogen receptor-α but not -β or GPER inhibits high glucose-induced human VSMC proliferation: potential role of ROS and ERK.

Context: The decreased incidence of cardiovascular disease in premenopausal women has been attributed, at least partially, to protective effects of estrogens. However, premenopausal women with diabetes mellitus are no longer selectively protected. High-glucose (HG) conditions have previously been shown to abolish the antimitogenic effects of 17β-estradiol (E(2)) in vascular smooth muscle cells (VSMCs).