Inge Wijnbergen

Safety and performance of the drug-eluting absorbable metal scaffold (DREAMS) in patients with de-novo coronary lesions: 12 month results of the prospective, multicentre, first-in-man BIOSOLVE-I trial

BACKGROUND Bioabsorbable vascular scaffolds were developed to overcome limitations of permanent bare-metal or drug-eluting coronary stents—ie, stent thrombosis (despite prolonged dual antiplatelet therapy), the life-long presence of a caged vessel segment that does not allow vasomotion or remodelling, and chronic vessel wall inflammation. We assessed the safety and performance of a new magnesium-based paclitaxel-eluting absorbable metal scaffold in symptomatic patients with de-novo coronary lesions. METHODS We did a prospective, multicentre, first-in-man trial (BIOSOLVE-1) of the drug-eluting absorbable metal scaffold (DREAMS). 46 patients with 47 lesions were enrolled at five European centres. The primary endpoint was target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularisation, at 6 and 12 months. Clinical follow-up was scheduled at 1, 6, 12, 24, and 36 months. Patients were consecutively assigned to angiographic and intravascular ultrasonographic follow-up at 6 months or 12 months. Optical coherence tomography was done in some patients. All patients were recommended to take dual antiplatelet therapy for at least 12 months. This trial is registered with ClinicalTrials.gov, number NCT01168830. FINDINGS Overall device and procedural success was 100%. Two of 46 (4%) patients had target lesion failure at 6 months (both clinically driven target lesion revascularisations), which rose to three of 43 (7%) at 12 months (one periprocedural target vessel myocardial infarction occurred during angiography at the 12 month follow-up visit). We noted no cardiac death or scaffold thrombosis. INTERPRETATION Our results show feasibility, a good safety profile, and promising clinical and angiographic performance results up to 12 months for DREAMS. Our promising clinical results show that absorbable metal scaffolds might be an alternative to polymeric absorbable scaffolds. FUNDING Biotronik.

Gender differences in long-term outcome after primary percutaneous intervention for ST-segment elevation myocardial infarction

Previous studies on gender differences in outcome in patients with ST segment elevation myocardial infarction (STEMI) have been performed, but most of those are from before the current era of PCI technique and medical therapy and have a short duration of follow‐up. The objective of our study is to assess the influence of gender on long‐term outcome in patients with STEMI who underwent primary percutaneous intervention (PCI) between January 2006 and May 2008.

Comparison of drug-eluting and Bare-metal stents for primary percutaneous coronary intervention with or without Abciximab in ST-segment elevation myocardial infarction DEBATER : the Eindhoven Reperfusion Study

OBJECTIVES The goal of this study was to demonstrate superiority of sirolimus-eluting stents (SES) over bare-metal stents (BMS) and of abciximab over no abciximab in primary percutaneous coronary intervention (PCI). BACKGROUND Drug-eluting stents (DES) are increasingly used in primary PCI, but the recommendations for use in primary PCI are based on a few randomized controlled trials with selected patients. The usefulness of abciximab in primary PCI is not established. METHODS Nine hundred seven patients referred to the Catharina Hospital were randomized to SES or BMS, and to abciximab or no abciximab in a prospective, randomized, open 2 × 2 factorial trial with blinded evaluation. Primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), defined as the composite of death, myocardial infarction (MI), stroke, repeat revascularization, and bleeding at 1 year (stent arm) and the composite of death, target vessel MI, target vessel revascularization (TVR), and bleeding at 30 days (abciximab arm). RESULTS At 1 year, the rate of MACCE was lower in the SES arm (16.5% vs. 25.8%, p = 0.001), mainly driven by less repeat revascularization (9.8% vs. 16.8%; p = 0.003) and without influencing the cumulative incidence of death and MI (5.2% vs. 5.8%; p = 0.68). At 30 days, the rate of the composite of death, target vessel MI, TVR, and bleeding was lower in the abciximab arm (8.2% vs. 12.4%, p = 0.04), mainly driven by less TVR due to less stent thrombosis (1.2% vs.7.4%, p < 0.001). However, bleeding complications occurred more frequently in the abciximab group (5.7% vs. 2.8%, p = 0.03). CONCLUSIONS Primary PCI with SES reduces adverse events at 1 year, mainly by reduction of repeat revascularization, whereas abciximab reduces early stent thrombosis, at the expense of more bleeding complications. (Comparison of Drug Eluting and Bare Metal Stents With or Without Abciximab in ST Elevation Myocardial Infarction [DEBATER]; NCT00986050).

Single bolus intravenous regadenoson injection versus central venous infusion of adenosine for maximum coronary hyperaemia in fractional flow reserve measurement

AIMS The aim of this study was to compare the hyperaemic effect of a single bolus regadenoson injection to a central venous adenosine infusion for inducing hyperaemia in the measurement of fractional flow reserve (FFR). METHODS AND RESULTS One hundred patients scheduled for FFR measurement were enrolled. FFR was first measured by IV adenosine (140 µg/kg/min), thereafter by IV bolus regadenoson injection (400 µg), followed by another measurement by IV adenosine and bolus injection of regadenoson. The regadenoson injections were randomised to central or peripheral intravenous. Hyperaemic response and duration of steady state maximum hyperaemia were studied, central versus peripheral venous regadenoson injections were compared, and safety and reproducibility of repeated injections were investigated. Mean age was 66±8 years, 75% of the patients were male. The target stenosis was located in the LM, LAD, LCX, and RCA in 7%, 54%, 20% and 19%, respectively. There was no difference in FFR measured by adenosine or by regadenoson (ΔFFR=0.00±0.01, r=0.994, p<0.001). Duration of maximum hyperaemia after regadenoson was variable (10-600 s). No serious side effects of either drug were observed. CONCLUSIONS Maximum coronary hyperaemia can be achieved easily, rapidly, and safely by one single intravenous bolus of regadenoson administered either centrally or peripherally. Repeated regadenoson injections are safe. The hyperaemic plateau is variable. Clinical Trial Registration: http://clinicaltrials.gov/ct2/ show/study/NCT01809743?term=NCT01809743&rank=1 (ClinicalTrials.gov Identifier: NCT01809743).

Novel monorail infusion catheter for volumetric coronary blood flow measurement in humans: in vitro validation

AIMS The aim of this study is to validate a novel monorail infusion catheter for thermodilution-based quantitative coronary flow measurements. METHODS AND RESULTS Based on the principles of thermodilution, volumetric coronary flow can be determined from the flow rate of a continuous saline infusion, the temperature of saline when it enters the coronary artery, and the temperature of the blood mixed with the saline in the distal part of the coronary artery. In an in vitro set-up of the systemic and coronary circulation at body temperature, coronary flow values were varied from 50-300 ml/min in steps of 50 ml/min. At each coronary flow value, thermodilution-based measurements were performed at infusion rates of 15, 20, and 30 ml/min. Temperatures and pressures were simultaneously measured with a pressure/temperature sensor-tipped guidewire. Agreement of the calculated flow and the measured flow as well as repeatability were assessed. A total of five catheters were tested, with a total of 180 measurements. A strong correlation (ρ=0.976, p<0.0001) and a difference of -6.5±15.5 ml/min were found between measured and calculated flow. The difference between two repeated measures was 0.2%±8.0%. CONCLUSIONS This novel infusion catheter used in combination with a pressure/temperature sensor-tipped guidewire allows accurate and repeatable absolute coronary flow measurements. This opens a window to a better understanding of the coronary microcirculation.

Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase ☆

BACKGROUND/PURPOSE In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR). METHODS Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3-5days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk. RESULTS The average time needed for measurement of absolute flow, resistance and IMR was 20min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68ml/min/g (p=0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p=0.40) between the first day and fifth day after STEMI. CONCLUSIONS Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI.

Circadian and weekly variation and the influence of environmental variables in acute myocardial infarction

ObjectivesThe aim of our study was to investigate the circadian and weekly variation and assess the influence of environmental variables on the occurrence of acute myocardial infarction (AMI).MethodsOur study population consisted of 2983 consecutive patients admitted with AMI between January 2006 and May 2008. Data were abstracted from hospital records and partially from an electronic database. In patients with a known time of onset of AMI, circadian variation was analysed. In all patients, weekly variation of onset of AMI was analysed. Information on daily mean temperature, sunny hours, rainy hours, maximal humidity and mean atmospheric pressure was obtained from the KNMI database and the influence of these environmental variables on the incidence of AMI was analysed.Results and conclusionIncidence of AMI shows a circadian pattern with an increase in occurrence during daylight. AMI occurs equally on each day of the week and no relation was found between environmental variables and the occurrence of AMI.

Safety and feasibility of local myocardial hypothermia.

In ST‐elevation myocardial infarction (STEMI), reduction in time to reperfusion of the occluded coronary artery reduces infarct size. In animal models, an additional reduction of infarct size was observed when hypothermia was induced before reperfusion, despite a longer ischemic time. However, several human studies did not corroborate this positive effect, which is believed to be in part due to the inability of systemic induced hypothermia to induce sufficient decrease of local myocardial temperature before reperfusion. Providing rapid local myocardial hypothermia by intracoronary infusion of saline before reperfusion in patients with STEMI may overcome this problem. In this study, we evaluate the safety and feasibility of providing rapid intracoronary myocardial hypothermia in patients undergoing intracoronary blood flow measurements based on thermodilution with continuous infusion of saline at room temperature.

Pressure gradient vs. flow relationships to characterize the physiology of a severely stenotic aortic valve before and after transcatheter valve implantation

Abstract Aims Echocardiography and tomographic imaging have documented dynamic changes in aortic stenosis (AS) geometry and severity during both the cardiac cycle and stress-induced increases in cardiac output. However, corresponding pressure gradient vs. flow relationships have not been described. Methods and results We recruited 16 routine transcatheter aortic valve implantations (TAVI’s) for graded dobutamine infusions both before and after implantation; 0.014″ pressure wires in the aorta and left ventricle (LV) continuously measured the transvalvular pressure gradient (ΔP) while a pulmonary artery catheter regularly assessed cardiac output by thermodilution. Before TAVI, ΔP did not display a consistent relationship with transvalvular flow (Q). Neither linear resistor (median R2 0.16) nor quadratic orifice (median R2 < 0.01) models at rest predicted stress observations; the severely stenotic valve behaved like a combination. The unitless ratio of aortic to left ventricular pressures during systolic ejection under stress conditions correlated best with post-TAVI flow improvement. After TAVI, a highly linear relationship (median R2 0.96) indicated a valid valve resistance. Conclusion Pressure loss vs. flow curves offer a fundamental fluid dynamic synthesis for describing aortic valve pathophysiology. Severe AS does not consistently behave like an orifice (as suggested by Gorlin) or a resistor, whereas TAVI devices behave like a pure resistor. During peak dobutamine, the ratio of aortic to left ventricular pressures during systolic ejection provides a ‘fractional flow reserve’ of the aortic valve that closely approximates the complex, changing fluid dynamics. Because resting assessment cannot reliably predict stress haemodynamics, ‘valvular fractional flow’ warrants study to explain exertional symptoms in patients with only moderate AS at rest.

Long-term comparison of sirolimus-eluting and bare-metal stents in ST-segment elevation myocardial infarction.

ObjectivesWe aimed to investigate, in patients with ST-segment elevation myocardial infarction (STEMI), whether the previously reported clinical benefits of sirolimus-eluting stent(s) (SES) in terms of reducing a major adverse cardiac and cerebrovascular event (MACCE) compared with bare-metal stent(s) (BMS) were maintained over a 5-year time period. BackgroundIn the prospective single-centre randomized DEBATER trial, SES significantly reduced the rate of MACCE in STEMI patients within 1 year compared with BMS, mainly driven by a reduction of target lesion revascularization. Randomized data on the long-term safety and efficacy of SES in STEMI patients are conflicting and limited. Patients and methodsBetween January 2006 and May 2008, a total of 907 STEMI patients were randomized to receive SES or BMS. The primary endpoint was MACCE defined as the composite of death, myocardial infarction, stroke, repeat revascularization and bleeding. Five-year follow-up data were collected by reviewing hospital records, telephone calls and a written questionnaire. ResultsAt 5 years, the rate of MACCE between the SES group and the BMS group was no longer significantly different (33.3 vs. 39.3%, P=0.12). The cumulative incidence of death and myocardial infarction was similar in both groups (11.0 vs. 9.7%, P=0.51). Repeat revascularization was performed in 21.1 and 25.8% of patients, respectively (P=0.12). The rate of very late stent thrombosis (1–5 years of follow-up) was very low in both groups (2.0 vs. 0.7%, P=0.12). ConclusionThe benefits of SES in STEMI patients in terms of reducing MACCE faded over time. We found no safety concerns in terms of SES in the long term, with extremely low rates of very late stent thrombosis.