M Wolfrum

A tool for predicting the outcome of reperfusion in ST-elevation myocardial infarction using age, thrombotic burden and index of microcirculatory resistance (ATI score).

AIMSnRestoration of effective myocardial reperfusion by primary percutaneous coronary intervention (PPCI) in patients with ST-elevation myocardial infarction is difficult to predict. A method to assess the likelihood of a suboptimal response to conventional pharmacomechanical therapies could be beneficial. We aimed to derive and validate a scoring system that can be used acutely at the time of coronary reopening to predict the likelihood of downstream microvascular impairment in patients with STEMI.nnnMETHODS AND RESULTSnA score estimating the risk of post-procedural microvascular injury defined by an index of microcirculatory resistance (IMR) >40 was initially derived in a cohort of 85 STEMI patients (derivation cohort). This score was then tested and validated in three further cohorts of patients (retrospective [30 patients], prospective [42 patients] and external [29 patients]). The ATI score (age [>50=1]; pre-stenting IMR [>40 and <100=1; ≥100=2]; thrombus score [4=1; 5=3]) was highly predictive of a post-stenting IMR >40 in all four cohorts (AUC: 0.87; p<0.001-derivation cohort, 0.84; p=0.002-retrospective cohort, 0.92; p<0.001-prospective cohort and 0.81; p=0.006-external cohort). In the whole population, an ATI score ≥4 presented a 95.1% risk of final IMR >40, while no cases of final IMR >40 occurred in the presence of an ATI score <2.nnnCONCLUSIONSnThe ATI score appears to be a promising tool capable of identifying patients during PPCI who are at the highest risk of coronary microvascular impairment following revascularisation. This procedural risk stratification has a number of potential research and clinical applications and warrants further investigation.

Role of deferred stenting in patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention: A systematic review and meta-analysis

OBJECTIVESnWe conducted a meta-analysis of studies comparing deferred stenting strategy versus the conventional approach with immediate stenting in patients with ST elevation myocardial infarction.nnnBACKGROUNDnDeferring stent after mechanical flow restoration has been proposed as a strategy to reduce the risk of no reflow in patients with STEMI undergoing primary percutaneous coronary intervention (pPCI). Conflicting evidence is available currently, especially after the recent publication of three randomized clinical trials.nnnMETHODSnSearches in electronic databases were performed. Comparisons between the two strategies were performed for both hard clinical endpoints (all cause-mortality, cardiovascular mortality, unplanned revascularization, myocardial infarction and readmission for heart failure) and surrogate angiographic endpoints (TIMI flowu2009<u20093 and myocardial blush grade (MBG)u2009<u20092).nnnRESULTSnEight studies (three randomized and five non-randomized) were deemed eligible, accounting for a total of 2101 patients. No difference in terms of hard clinical endpoints was observed between deferred and immediate stenting (OR [95% CI]: 0.79 [0.54-1.15], for all-cause mortality; odds ratio (OR) [95% CI]: 0.79 [0.47-1.31] for cardiovascular mortality; OR [95% CI]: 0.95 [0.64-1.41] for myocardial infarction; OR [95% CI]: 1.37 [0.87-2.16], for unplanned revascularization and OR [95% CI]: 0.50 [0.21-1.17] for readmission for heart failure). Notably, the deferred stenting approach was associated with improved outcome of the surrogate angiographic endpoints (OR [95% CI]: 0.43 [0.18-0.99] of TIMI flowu2009<u20093 and OR [95% CI]: 0.25 [0.11-0.57] for MBGu2009<u20092.nnnCONCLUSIONSnA deferred stenting strategy could be a feasible alternative to the conventional approach with immediate stenting in selected STEMI patients undergoing pPCI.

The ATI score (age-thrombus burden-index of microcirculatory resistance) determined during primary percutaneous coronary intervention predicts final infarct size in patients with ST-elevation myocardial infarction: a cardiac magnetic resonance validation study

AIMSnThe age-thrombus burden-index of microcirculatory resistance (ATI) score is a diagnostic tool able to predict suboptimal myocardial reperfusion before stenting, in patients with ST-elevation myocardial infarction (STEMI). We aimed to validate the ATI score against cardiac magnetic resonance imaging (cMRI).nnnMETHODS AND RESULTSnThe ATI score was calculated prospectively in 80 STEMI patients. cMRI was performed within 48 hours in all patients and in 50 patients at six-month follow-up to assess the extent of infarct size (IS%) and microvascular obstruction (MVO%). The ATI score was calculated using age (>50=1 point), pre-stenting index of microcirculatory resistance (IMR) (>40 and <100=1 point; ≥100=2 points) and angiographic thrombus score (4=1 point; 5=3 points). ATI score was closely related to final IS% (ATI.

The influence of coronary plaque morphology assessed by optical coherence tomography on final microvascular function after stenting in patients with ST-elevation myocardial infarction.

Objectives The index of microcirculatory resistance (IMR) provides a reproducible assessment of the status of coronary microvasculature in patients with ST-elevation myocardial infarction (STEMI). Frequency-domain optical coherence tomography (FD-OCT) enables detailed assessment of the morphology of coronary plaque. We sought to determine the influence of the initial culprit coronary plaque anatomy within the infarct-related artery on IMR after stenting in STEMI. Patients and methods In 25 STEMI patients IMR was measured immediately before and after stent implantation. FD-OCT imaging was performed at the same time points and atherothrombotic volume (ATV) before stenting, prolapsed+floating ATV after stenting and &Dgr;ATV was measured using three different strategies. Results There were no relationships between preprocedural IMR and FD-OCT parameters. Prestenting IMR was related only to pain to wire time (P: 0.02). Irrespective of the method adopted, the final IMR was related to prestenting ATV (&rgr;: 0.44, P: 0.03 for method I, &rgr;: 0.48, P: 0.02 for method II and &rgr;: 0.30, P: 0.06 for method III) and &Dgr;ATV (&rgr;: 0.41, P: 0.04 for method II and &rgr;: 0.44, P: 0.03 for method III). Conclusion IMR measured before stenting is independent of the appearances of the culprit coronary plaque within the infarct-related artery. IMR after stenting, and more importantly, the change in IMR after stenting, reflect the degree of distal embolization during stent implantation.

Impact of impaired fractional flow reserve after coronary interventions on outcomes: a systematic review and meta-analysis

BackgroundFFR is routinely used to guide percutaneous coronary interventions (PCI). Visual assessment of the angiographic result after PCI has limited efficacy. Even when the angiographic result seems satisfactory FFR after a PCI might be useful for identifying patients with a suboptimal interventional result and higher risk for poor clinical outcome who might benefit from additional procedures. The aim of this meta-analysis was to investigate available data of studies that examined clinical outcomes of patients with impaired vs. satisfactory fractional flow reserve (FFR) after percutaneous coronary interventions (PCI).MethodsThis meta-analysis was carried out according to the Cochrane Handbook for Systematic Reviews. The Mantel-Haenszel method using the fixed-effect meta-analysis model was used for combining the results. Studies were identified by searching the literature through mid-January, 2016, using the following search terms: fractional flow reserve, coronary circulation, after, percutaneous coronary intervention, balloon angioplasty, stent implantation, and stenting. Primary endpoint was the rate of major adverse cardiac events (MACE). Secondary endpoints included rates of death, myocardial infarction (MI), repeated revascularisation.ResultsEight relevant studies were found including a total of 1337 patients. Of those, 492 (36.8xa0%) had an impaired FFR after PCI, and 853 (63.2xa0%) had a satisfactory FFR after PCI. Odds ratios indicated that a low FFR following PCI was associated with an impaired outcome: major adverse cardiac events (MACE, OR: 4.95, 95xa0% confidence interval [CI]: 3.39–7.22, p <0.001); death (OR: 3.23, 95xa0% CI: 1.19–8.76, pu2009=u20090.022); myocardial infarction (OR: 13.83, 95xa0% CI: 4.75–40.24, p <0.0001) and repeated revascularisation (OR: 4.42, 95xa0% CI: 2.73–7.15, p <0.0001).ConclusionsCompared to a satisfactory FFR, a persistently low FFR following PCI is associated with a worse clinical outcome. Prospective studies are needed to identify underlying causes, determine an optimal threshold for post-PCI FFR, and clarify whether simple additional procedures can influence the post-PCI FFR and clinical outcome.

Index of Microcirculatory Resistance at the Time of Primary Percutaneous Coronary Intervention Predicts Early Cardiac Complications: Insights From the OxAMI (Oxford Study in Acute Myocardial Infarction) Cohort

Background Early risk stratification after primary percutaneous coronary intervention (PPCI) for ST‐segment–elevation myocardial infarction is currently challenging. Identification of a low‐risk group may improve triage of patients to alternative clinical pathways and support early hospital discharge. Our aim was to assess whether the index of microcirculatory resistance (IMR) at the time of PPCI can identify patients at low risk of early major cardiac complications and to compare its performance against guideline‐recommended risk scores. Methods and Results IMR was measured using a pressure–temperature sensor wire. Cardiac complications were defined as the composite of cardiac death, cardiogenic shock, pulmonary edema, malignant arrhythmias, cardiac rupture, and presence of left ventricular thrombus either before hospital discharge or within 30‐day follow‐up. In total, 261 patients undergoing PPCI who were eligible for coronary physiology assessment were prospectively enrolled. Twenty‐two major cardiac complications were reported. Receiver operating characteristic curve analysis confirmed the utility of IMR in predicting complications and showed significantly better performance than coronary flow reserve, the Primary Angioplasty in Myocardial Infarction II (PAMI‐II), and Zwolle score (P≤0.006). Low microvascular resistance (IMR ≤40) was measured in 159 patients (61%) of the study population and identified all patients who were free of major cardiac complications (sensitivity: 100%; 95% CI, 80.5–100%). Conclusions IMR immediately at the end of PPCI for ST‐segment–elevation myocardial infarction reliably predicts early major cardiac complications and performed significantly better than recommended risk scores. These novel data have implications for early risk stratification after PPCI.

Index of Microcirculatory Resistance as a Tool to Characterize Microvascular Obstruction and to Predict Infarct Size Regression in Patients With STEMI Undergoing Primary PCI

OBJECTIVESnThis study aimed to compare the value of the index of microcirculatory resistance (IMR) and microvascular obstruction (MVO) measured by cardiac magnetic resonance (CMR) in patients treated for and recovering from ST-segment elevation myocardial infarction.nnnBACKGROUNDnIMR can identify patients with microvascular dysfunction acutely after primary percutaneous coronary intervention (pPCI), and a threshold of >40 has been shown to be associated with an adverse clinical outcome. Similarly, MVO is recognized as an adverse feature in patients with ST-segment elevation myocardial infarction. Even though both IMR and MVO reflect coronary microvascular status, the interaction between these 2 parameters is uncertain.nnnMETHODSnA total of 110 patients treated with pPCI were included, and IMR was measured immediately at completion of pPCI. Infarct size (IS) as a percentage of left ventricular mass was quantified at 48 h (38.4 ± 12.0 h) and 6 months (194.0xa0± 20.0 days) using CMR. MVO was identified and quantified at 48 h by CMR.nnnRESULTSnOverall, a discordance between IMR and MVO was observed in 36.7% of cases, with 31 patients having MVO and IMRxa0≤40. Compared with patients with MVO and IMRxa0≤40, patients with both MVO and IMR >40 had an 11.9-fold increased risk of final IS >25% at 6 months (pxa0= 0.001). Patients with MVO and IMRxa0≤40 had a significantly smaller IS at 6 months (pxa0= 0.001), with significant regression in IS over time (34.4% [interquartile range (IQR): 27.3% to 41.0%] vs. 22.3% [IQR: 16.0% to 30.0%]; pxa0= 0.001).nnnCONCLUSIONSnDiscordant prognostic information was obtained from IMR and MVO in nearly one-third of cases; however, IMR can be helpful in grading the degree and severity of MVO.

1 The ATI score (age-thrombotic burden-index of microcirculatory resistance) in stemi: a cardiac magnetic resonance study

Background The age-thrombus score-index of microcirculatory resistance (ATI) score is a diagnostic tool recently applied by our group in ST elevation myocardial infarction (STEMI). It is able to predict suboptimal myocardial reperfusion early in the revascularisation process thus facilitating the triage of alternative or additional therapies to the conventional approach with stenting. We aimed to validate the ATI score against cardiac magnetic resonance imaging (cMRI). Methods The ATI score was calculated using age (>50=1u2009point), pre-stenting index of microcirculatory resistance (IMR) (>40u2009and <100=1u2009point; ≥100=2 points) and angiographic thrombus score (4=1u2009point; 5=3 points)]. cMRI scan was performed within 48u2009hours from admission and at 6 months follow up to assess the extent of infarct size (IS%) and microvascular obstruction (MVO%). Results The ATI score was calculated prospectively in 80 STEMI patients. cMRI scanning was performed within 48u2009hours in all patients and in 50 patients at six months follow up. ATI score was closely related to final IS% (ATI0-1: 18.0% [9.0–24.5], ATI2-3: 28.5% [12.8–43.0] and ATI4-5-6: 41.2% [22.0–44.4]u2009p: 0.001) and with MVO% (ATI0-1: 0.0% [0.0–0.9], ATI2-3: 0.7% [0.0–2.5] and ATI4-5-6: 4.1% [1.2–10.7], p<0.001). ATI score predicted final IS% at six months follow up (ATI0-1: 12.7% [4.5–22.0], ATI2-3-: 20.0% [6.4–25.6] and ATI4-5-6: 34.0% [22.2–46.5], p: 0.02). Conclusions The ATI score applied prior to stenting in patents with STEMI, can predict the likelihood of MVO% and IS% both acutely and at six months follow up cMRI.

Optical coherence tomography to guide percutaneous treatment of coronary bifurcation disease.

ABSTRACT Introduction: Cardiovascular disease remains the most common cause of death worldwide. Enormous progress in the technology and applicability of percutaneous techniques to treat obstructive coronary heart disease has been made, and the number of percutaneous coronary interventions (PCI) is increasing. Coronary bifurcations are involved in a substantial number of PCIs and despite recent advances, bifurcation PCI remains a challenge in terms of immediate success and long-term outcome. Angiography has a limited capacity for showing important features of the 3 dimensional coronary vessel anatomy, position of stent struts and exact wire positions and is therefore suboptimal for guiding bifurcation PCI. Intracoronary optical coherence tomography (OCT) provides high resolution and the information gained during PCI is unprecedented compared with angiography guidance and intravascular ultrasound. Areas covered: This review will provide an overview of the use of OCT to guide bifurcation-PCI. Expert commentary: OCT is a promising guide for bifurcation-PCI at each individual step: from planning the strategy (provisional versus two-stent strategy), to guidance during PCI, and finally checking the interventional result. Until dedicated randomized trails are complete, we recommend OCT guidance for interventions in complex coronary bifurcation disease and for imaging when unexpected procedural events occur.

PREDICTING THE OUTCOME OF REPERFUSION ACUTELY IN PATIENTS WITH STEMI - DERIVATION AND VALIDATION OF THE ATI SCORE

Aim Restoration of effective myocardial reperfusion by primary percutaneous coronary intervention (PPCI) in patients with STEMI is not predictable. A method to assess the likelihood of a suboptimal response to conventional pharmaco-mechanical therapies could be beneficial. We aimed to derive and validate a scoring system that can be used acutely at the time of coronary reopening to predict the likelihood of downstream microvascular impairment in patients with STEMI. Methods and Results A score estimating the risk of post-procedural microvascular injury defined by an index of microcirculatory resistance (IMR) > 40, was initially derived in a cohort of 85 STEMI patients (Derivation cohort). This score was then tested and validated in three further cohorts of patients (Retrospective (30 patients), Prospective (42 patients) and External (29 patients). The ATI score [Age ( > 50 = 1); pre-stenting IMR (> 40 and < 100 = 1; ≥ 100 = 2); Thrombus score (4=1; 5=3)] was highly predictive of a post-stenting IMR > 40 in all the four cohorts (AUC:0.87; p < 0.001-Derivation cohort, 0.84; p: 0.002-Retrospective cohort, 0.92; p < 0.001-Prospective cohort and 0.81; p: 0.006-External cohort). In the whole population an ATI score ≥ 4 presented a 95.1% risk of final IMR >40, while no cases of final IMR >40 occurred in the presence of an ATI score < 2. Conclusions The ATI score appears to be a promising tool capable of identifying patients during PPCI that are at the highest risk of an adverse outcome following revascularisation.