Left ventricular blood flow kinetic energy after myocardial infarction - insights from 4D flow cardiovascular magnetic resonance.

BACKGROUND: Myocardial infarction (MI) leads to complex changes in left ventricular (LV) haemodynamics that are linked to clinical outcomes. We hypothesize that LV blood flow kinetic energy (KE) is altered in MI and is associated with LV function and infarct characteristics. This study aimed to investigate the intra-cavity LV blood flow KE in controls and MI patients, using cardiovascular magnetic resonance (CMR) four-dimensional (4D) flow assessment. METHODS: Forty-eight patients with MI (acute-22; chronic-26) and 20 age/gender-matched healthy controls underwent CMR which included cines and whole-heart 4D flow. Patients also received late gadolinium enhancement imaging for infarct assessment. LV blood flow KE parameters were indexed to LV end-diastolic volume and include: averaged LV, minimal, systolic, diastolic, peak E-wave and peak A-wave KEiEDV. In addition, we investigated the in-plane proportion of LV KE (%) and the time difference (TD) to peak E-wave KE propagation from base to mid-ventricle was computed. Association of LV blood flow KE parameters to LV function and infarct size were investigated in all groups. RESULTS: LV KEiEDV was higher in controls than in MI patients (8.5 ± 3 µJ/ml versus 6.5 ± 3 µJ/ml, P = 0.02). Additionally, systolic, minimal and diastolic peak E-wave KEiEDV were lower in MI (P < 0.05). In logistic-regression analysis, systolic KEiEDV (Beta = - 0.24, P < 0.01) demonstrated the strongest association with the presence of MI. In multiple-regression analysis, infarct size was most strongly associated with in-plane KE (r = 0.5, Beta = 1.1, P < 0.01). In patients with preserved LV ejection fraction (EF), minimal and in-plane KEiEDV were reduced (P < 0.05) and time difference to peak E-wave KE propagation during diastole increased (P < 0.05) when compared to controls with normal EF. CONCLUSIONS: Reduction in LV systolic function results in reduction in systolic flow KEiEDV. Infarct size is independently associated with the proportion of in-plane LV KE. Degree of LV impairment is associated with TD of peak E-wave KE. In patient with preserved EF post MI, LV blood flow KE mapping demonstrated significant changes in the in-plane KE, the minimal KEiEDV and the TD. These three blood flow KE parameters may offer novel methods to identify and describe this patient population.

Amsterdam Investigator-initiateD Absorb strategy all-comers trial (AIDA trial): a clinical evaluation comparing the efficacy and performance of ABSORB everolimus-eluting bioresorbable vascular scaffold strategy vs the XIENCE family (XIENCE PRIME or XIENCE Xpedition) everolimus-eluting coronary stent strategy in the treatment of coronary lesions in consecutive all-comers: rationale and study design.

BACKGROUND: The Absorb everolimus-eluting bioresorbable vascular scaffold (AbsorbBVS) is a completely resorbable device engineered to overcome the limitations of permanent metallic stents, providing temporary scaffolding and antiproliferative drug delivery for the treatment of obstructive coronary artery disease. METHODS: The objective of the AIDA trial is to evaluate the efficacy and performance in an contemporary all-comer population of the AbsorbBVS strategy vs the XIENCE family everolimus-eluting metallic coronary stent system in the treatment of coronary lesions. The AIDA trial is a prospective, randomized (1:1), active-control, single-blinded, all-comer, noninferiority trial. A total of 2,690 subjects will be enrolled with broad inclusion and limited exclusion criteria according to the "Instructions for Use" of the AbsorbBVS strategy. The study population includes both simple and complex lesions, in patients with stable and acute coronary syndrome. The follow-up continues for 5years. The primary end point of the trial is target vessel failure, defined as the composite of cardiac death, myocardial infarction, and target vessel revascularization, at 2years. This study is registered on ClinicalTrials.gov with number NCT01858077. CONCLUSION: The AIDA trial will provide the first randomized direct comparison between the everolimus-eluting bioresorbable vascular scaffold and the everolimus-eluting metallic stent in contemporary percutaneous coronary intervention practice.

The stability of myocardial area at risk estimated electrocardiographically in patients with ST elevation myocardial infarction.

In patients with ST-elevation myocardial infarction (STEMI) the amount of myocardial area at risk (MaR) indicates the maximal potential loss of myocardium if the coronary artery remains occluded. During the time course of infarct evolution ischemic MaR is replaced by necrosis, which results in a decrease in ST segment elevation and QRS complex distortion. Recently it has been shown that combining the electrocardiographic (ECG) Aldrich ST and Selvester QRS scores result in a more accurate estimate of MaR than using either method alone. Therefore, we hypothesized that the combined Aldrich and Selvester score, indicating MaR, is stable until myocardial reperfusion therapy. In a retrospective analysis of a study population of 114 patients, 33 patients were included. The combined Aldrich and Selvester score was determined in ECGs recorded in the ambulance (ECG1) and in the hospital before reperfusion (ECG2). The combined Aldrich and Selvester score was considered stable if the difference between ECG1 and ECG2 was <4.5-percentage point. Stability of the combined Aldrich and Selvester score was observed in 12/33 patients (36.4%), and in regards to anterior and inferior ST elevation in 4/14 patients (28.6%) and 8/19 patients (42.1%), respectively. The median time between the recording of ECG1 and ECG2 was 75 minutes, however the changes in ECG scores were independent of the time between ECG recordings. Patients not meeting the stability criterion either had a decrease (9 patients) or increase (12 patients) of the combined Aldrich and Selvester score. In conclusion, the ECG estimated MaR was stable between the earliest recording time and initiation of reperfusion treatment only in a subgroup of the patients with STEMI. The findings of this study may suggest heterogeneity in regards to the development of the MaR and could indicate a potential need for differentiation in the acute treatment.

The predictive value of an ECG-estimated Acute Ischemia Index for prognosis of myocardial salvage and infarct healing 3months following inferior ST-elevated myocardial infarction.

BACKGROUND AND PURPOSE: Identification of prognostic markers can be used to stratify patients in the acute phase of ST-elevated myocardial infarction (STEMI) according to their potential to retain viable myocardium after reperfusion. The percentage of the myocardial area at risk (MaR) that is ischemic at admission, defined as the Acute Ischemia Index, is potentially salvageable. The percentage of the MaR viable at 3months post-reperfusion, by salvage and healing, was defined as the Chronic Salvage Index. A positive relationship between the Acute Ischemia Index and the Chronic Salvage Index was hypothesized. METHODS: Both indices were assessed by using the ECG indices Aldrich ST and Selvester QRS scores estimating the ischemic and infarcted myocardium. The study population comprised inferior STEMI patients. (N=59). RESULTS: A correlation of 0.253 (P=0.053) was found. CONCLUSIONS: These results are relevant and suggest evidence of a trend in the association between these indices.

Left ventricular four-dimensional blood flow distribution, energetics, and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus.

BACKGROUND: Left ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls. METHODS: In this prospective cohort study, the 4D flow CMR data were acquired in 19 chronic MI patients (MI-LVT(+), n = 9 and MI-LVT(-), n = 10) and 9 age-matched controls. All included subjects were in sinus rhythm. The following LV flow parameters were obtained: LV flow components (direct, retained, delayed, residual), mean and peak kinetic energy (KE) values (indexed to instantaneous LV volume), mean and peak vorticity values, and diastolic vortex ring properties (position, orientation, shape). RESULTS: The MI patients demonstrated a significantly larger amount of delayed and residual flow, and a smaller amount of direct flow compared to controls (p = 0.02, p = 0.03, and p < 0.001, respectively). The MI-LVT(+) patients demonstrated numerically increased residual flow and reduced retained and direct flow in comparison to MI-LVT(-) patients. Systolic mean and peak LV blood flow KE values were significantly lower in MI patients compared to controls (p = 0.04, p = 0.03, respectively). Overall, the mean and peak LV vorticity values were significantly lower in MI patients compared to controls. The mean and peak systolic vorticity at the basal level were significantly higher in MI-LVT(+) than in MI-LVT(-) patients (p < 0.01, for both). The vortex ring core during E-wave in MI-LVT(+) group was located in a less tilted orientation to the LV compared to MI-LVT(-) group (p < 0.01). CONCLUSIONS: Chronic MI patients with LVT express a different distribution of LV flow components, irregular vorticity vector fields, and altered diastolic vortex ring geometric properties as assessed by 4D flow CMR. Larger prospective studies are warranted to further evaluate the significance of these initial observations.

Left ventricular thrombus formation in myocardial infarction is associated with altered left ventricular blood flow energetics.

Aims: The main aim of this study was to characterize changes in the left ventricular (LV) blood flow kinetic energy (KE) using four-dimensional (4D) flow cardiovascular magnetic resonance imaging (CMR) in patients with myocardial infarction (MI) with/without LV thrombus (LVT). Methods and results: This is a prospective cohort study of 108 subjects [controls = 40, MI patients without LVT (LVT- = 36), and MI patients with LVT (LVT+ = 32)]. All underwent CMR including whole-heart 4D flow. LV blood flow KE wall calculated using the formula: KE=12 ρblood . Vvoxel . v2, where ρ = density, V = volume, v = velocity, and was indexed to LV end-diastolic volume. Patient with MI had significantly lower LV KE components than controls (P < 0.05). LVT+ and LVT- patients had comparable infarct size and apical regional wall motion score (P > 0.05). The relative drop in A-wave KE from mid-ventricle to apex and the proportion of in-plane KE were higher in patients with LVT+ compared with LVT- (87 ± 9% vs. 78 ± 14%, P = 0.02; 40 ± 5% vs. 36 ± 7%, P = 0.04, respectively). The time difference of peak E-wave KE demonstrated a significant rise between the two groups (LVT-: 38 ± 38 ms vs. LVT+: 62 ± 56 ms, P = 0.04). In logistic-regression, the relative drop in A-wave KE (beta = 11.5, P = 0.002) demonstrated the strongest association with LVT. Conclusion: Patients with MI have reduced global LV flow KE. Additionally, MI patients with LVT have significantly reduced and delayed wash-in of the LV. The relative drop of distal intra-ventricular A-wave KE, which represents the distal late-diastolic wash-in of the LV, is most strongly associated with the presence of LVT.

Microvascular dysfunction following ST-elevation myocardial infarction and its recovery over time.

AIMS: It is unclear whether microvascular dysfunction following ST-elevation myocardial infarction (STEMI) is prognostic for long-term left ventricular function (LVF), and whether recovery of the microvasculature status is associated with LVF improvement. The aim of this study was to assess whether microvascular dysfunction in the infarct-related artery (IRA), as assessed by coronary flow reserve (CFR) within one week after PPCI, was associated with LVF at both four months and two years. METHODS AND RESULTS: In 62 patients, CFR and hyperaemic microvascular resistance index (HMRI) in the IRA were assessed by intracoronary Doppler flow measurements within one week and at four months. CMR was performed at the same time points and also at two years. CFR at baseline was associated with left ventricular ejection fraction (LVEF) at four months (ß=4.66, SE=2.10; p=0.03) and at two-year follow-up (ß=5.84, SE=2.45; p=0.02). HMRI was not associated with LVF. In large infarcts, absolute improvement of CFR in the first four months was associated with LVEF improvement (ß=5.09, SE=1.86, p=0.01). CONCLUSIONS: Microvascular dysfunction, assessed by CFR, in the subacute phase of STEMI is prognostic for LVEF at four months and two years. This underlines the pivotal role of microvascular dysfunction following STEMI.

Predictors and prognostic consequence of gastrointestinal bleeding in patients with ST-segment elevation myocardial infarction.

BACKGROUND: Limited data are available on the predictors and implications of gastrointestinal (GI) bleeding in ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PPCI) and dual antiplatelet therapy. METHODS AND RESULTS: Predictors of and clinical outcome after GI bleeding were assessed in 2002 STEMI patients undergoing PPCI between 1-1-2003 and 31-07-2008. 139 patients suffered GI bleeding during a median follow-up of 4.9 years. Predictors of GI bleeding were age, history of bleeding, anemia, baseline thrombocytopenia, previous coronary artery bypass grafting, cardiogenic shock, anterior infarction and the use of GP IIb/IIIa inhibitor. By multivariable analysis, a first occurrence of GI bleeding was associated with a twofold increase in risk of subsequent GI bleeding (hazard ratio (HR) 2.19; 95% confidence interval (CI) 1.15-4.17). GI bleeding was not significantly associated with subsequent major adverse cardiac events (HR 1.33; 95% CI 0.98-1.79), cardiac (HR 1.40; 95% CI 0.97-2.02) and all-cause mortality (HR 1.34; 95% CI 0.96-1.85), recurrent MI (HR 0.97; 95% CI 0.58-1.63), stroke (HR 1.26; 95% CI 0.57-2.79) or stent thrombosis (HR 0.71; 95% CI 0.33-1.69). CONCLUSION: Among STEMI patients undergoing PPCI, the risk of GI bleeding is related to a number of risk factors, including advanced age, previous (GI) bleeding, GP IIB/IIIA inhibitors, anterior infarction and anemia. GI bleeding does not substantially increase the risk of subsequent recurrent ischemic events in STEMI patients undergoing PPCI, whereas the risk of GI bleeding after a first occurrence is more than doubled.

Initial experience and clinical evaluation of the Absorb bioresorbable vascular scaffold (BVS) in real-world practice: the AMC Single Centre Real World PCI Registry.

AIMS: To report procedural and midterm clinical outcomes after the use of the second-generation Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) in a real-world percutaneous coronary intervention (PCI) registry. METHODS AND RESULTS: All patients assigned to treatment with the Absorb BVS in the Academic Medical Center, Amsterdam, between August 2012 and August 2013 were included in a prospective registry. A total of 135 patients were included in the study, including 53 (39%) acute coronary syndrome (ACS) patients (13% ST-segment elevation myocardial infarction [STEMI]). In total 159 lesions were treated, including 102 (62%) with a type B2 or C classification. Pre- and post-procedural quantitative coronary angiography (QCA) analyses showed an acute gain of 1.37±0.53 mm. An angiographic success rate was achieved in 152 (96%) of the lesions. Six-month follow-up was available in 97% of the patients. Six-month cumulative target vessel failure (composite of all-cause mortality, any myocardial infarction [MI] and target vessel revascularisation [TVR]) rate was 8.5%, including a 3.0% MI, 3.0% definite scaffold thrombosis, 6.3% target lesion revascularisation, and an 8.5% TVR rate. CONCLUSIONS: The use of the Absorb BVS in a cohort reflecting daily clinical practice is feasible and associated with good procedural safety and angiographic success rate. In addition, six-month follow-up is associated with acceptable clinical outcomes.

Treatment of coronary bifurcation lesions with the Absorb bioresorbable vascular scaffold in combination with the Tryton dedicated coronary bifurcation stent: evaluation using two- and three-dimensional optical coherence tomography.

AIMS: The Tryton bifurcation stent has been developed to improve clinical outcomes after treatment of bifurcation lesions. Limited data are available on the use of the Absorb bioresorbable vascular scaffold (BVS) in bifurcation lesions with side branches >2 mm. We present here the acute procedural results and midterm clinical follow-up of the first-in-man combined use of the Tryton stent and the Absorb scaffold for the treatment of complex bifurcation lesions. METHODS AND RESULTS: Ten patients treated with the Tryton stent in combination with Absorb BVS were included in the current report. Offline two- and three-dimensional optical coherence tomography (OCT) analyses were performed to gain more insights into this novel approach. Procedural success was 91%, whereas angiographic success was achieved in 82%. Two TLRs occurred (TLR rate 20%), whereas no deaths, myocardial infarctions or stent thromboses were observed up to six months of follow-up. CONCLUSIONS: We present a new treatment strategy in complex bifurcation lesions using the Tryton stent in combination with the Absorb BVS. This approach potentially offers an opportunity to treat complex bifurcation lesions with the Absorb BVS. Furthermore, three-dimensional OCT reconstructions give valuable insights into PCI of complex bifurcation lesions.

Antiplatelet therapy following transcatheter aortic valve implantation.

OBJECTIVE: There is limited evidence to support decision making on antiplatelet therapy following transcatheter aortic valve implantation (TAVI). Our aim was to assess the efficacy and safety of aspirin-only (ASA) versus dual antiplatelet therapy (DAPT) following TAVI. METHODS: We performed a systematic review and pooled analysis of individual patient data from 672 participants comparing single versus DAPT following TAVI. Primary endpoint was defined as the composite of net adverse clinical and cerebral events (NACE) at 1 month, including all-cause mortality, acute coronary syndrome (ACS), stroke, life-threatening and major bleeding. RESULTS: At 30 days a NACE rate of 13% was observed in the ASA-only and in 15% of the DAPT group (OR 0.83, 95% CI 0.48 to 1.43, p=0.50). A tendency towards less life-threatening and major bleeding was observed in patients treated with ASA (OR 0.56, 95% CI 0.28 to 1.11, p=0.09). Also, ASA was not associated with an increased all-cause mortality (OR 0.91, 95% CI 0.36 to 2.27, p=0.83), ACS (OR 0.5, 95% CI 0.05 to 5.51, p=0.57) or stroke (OR 1.21; 95% CI 0.36 to 4.03, p=0.75). CONCLUSIONS: No difference in 30-day NACE rate was observed between ASA-only or DAPT following TAVI. Moreover, a trend towards less life-threatening and major bleeding was observed in favour of ASA. Consequently the additive value of clopidogrel warrants further investigation.

Impaired Coronary Autoregulation Is Associated With Long-term Fatal Events in Patients With Stable Coronary Artery Disease.

BACKGROUND: Abnormalities in the coronary microcirculation are increasingly recognized as an elementary component of ischemic heart disease, which can be accurately assessed by coronary flow velocity reserve in reference vessels (refCFVR). We studied the prognostic value of refCFVR for long-term mortality in patients with stable coronary artery disease. METHODS AND RESULTS: We included patients with stable coronary artery disease who underwent intracoronary physiological evaluation of ≥ 1 coronary lesion of intermediate severity between April 1997 and September 2006. RefCFVR was assessed if a coronary artery with <30% irregularities was present. RefCFVR >2.7 was considered normal. Patients underwent revascularization of all ischemia-causing lesions. Long-term follow-up was performed to document the occurrence of (cardiac) mortality. RefCFVR was determined in 178 patients. Kaplan-Meier estimates of 12-year all-cause mortality were 16.7% when refCFVR >2.7 and 39.6% when refCFVR ≤ 2.7 (P<0.001), whereas Kaplan-Meier estimates for cardiac mortality were 7.7% when refCFVR >2.7 and 31.6% when refCFVR ≤ 2.7 (P<0.001). After multivariable adjustment, refCFVR ≤ 2.7 was associated with a 2.24-fold increase in all-cause mortality hazard (hazard ratio, 2.24; 95% confidence interval, 1.13-4.44; P=0.020) and a 3.32-fold increase in cardiac mortality hazard (hazard ratio, 3.32; 95% confidence interval, 1.27-8.67; P=0.014). Impairment of refCFVR originated from significantly higher baseline flow velocity in the presence of significantly lower reference vessel baseline microvascular resistance (P<0.001), indicating impaired coronary autoregulation as its cause. CONCLUSIONS: In patients with stable coronary artery disease, impaired refCFVR, resulting from increased baseline flow velocity indicating impaired coronary autoregulation, is associated with a significant increase in fatal events at long-term follow-up.

[The bioresorbable coronary scaffold]. / De biologisch oplosbare coronaire stent.

The routine placement of permanent metal stents has led to an improvement of the long-term and short-term effects of percutaneous coronary interventions. Treatment with the newest generation of drug-eluting stents results in a low risk of restenosis. The antiproliferative drug eluted by these stents, however, prevents endothelialisation; this leads to an increased risk of exposed metallic stent parts, which in turn leads to a higher risk of stent thrombosis. There is evidence that the vessel wall support provided by the stent is only a temporary requirement. Permanent metallic stents could, therefore, be superfluous in the long term. A bioresorbable vascular scaffold (BVS), manufactured from polylactic acid and completely resorbed within 18-24 months, is a new alternative. It is expected that these scaffolds will lead to the disappearance of the risk of late stent thrombosis. Theoretically, the bioresorbable vascular scaffold also provides a considerable advantage for patients who will probably have to undergo further coronary intervention in the future. Metal stents can be an important limiting factor for these patients.