BACKGROUND:Intravenous adenosine induces stable myocardial hyperemia for coronary microvascular function testing. Iodinated radiographic contrast media induce transient, submaximal hyperemia. We assessed the feasibility, diagnostic value, and potential cost-effectiveness of contrast-derived indices of microvascular function. METHODS:Coronary flow reserve, index of microvascular resistance, and microvascular resistance reserve were assessed using a diagnostic guidewire. Intracoronary bolus thermodilution injections were performed at rest, immediately after an 8-mL bolus of iohexol, repeated after a second 8-mL bolus, and during intravenous adenosine infusion. Receiver operating characteristic analyses assessed the discriminatory ability of the contrast-derived indices (contrast-derived coronary flow reserve, contrast-derived index of microcirculatory resistance, contrast-derived microvascular resistance reserve) to detect abnormal adenosine-derived indices (coronary flow reserve <2.0, index of microvascular resistance ≥25, and microvascular resistance reserve <2.1). RESULTS:Among 106 coronary arteries from 93 patients (median age 63 years; 62% women; 13% with diabetes), 88% of assessments were undertaken in the left anterior descending artery. Median fractional flow reserve was 0.88 (interquartile range, 0.85-0.92). Contrast-derived coronary flow reserve <2.0 (area under the curve 0.81; sensitivity 67%, specificity 80%, positive predictive value 40%, negative predictive value 92%), contrast-derived index of microcirculatory resistance >47 (area under the curve 0.82; 80%, 79%, 60%, 91%), and contrast-derived microvascular resistance reserve <1.9 (area under the curve 0.82; 67%, 89%, 35%, 97%) were best for predicting their adenosine-derived counterpart indices. There was good correlation on repeatability testing from the second contrast bolus. A hybrid approach reduced adenosine use by 40%, saving $30 800 (USA) or £8000 (UK) per 1000 vessels assessed. CONCLUSIONS:Contrast-derived indices have high specificity and negative predictive value, enabling rapid exclusion of microvascular dysfunction. This method is feasible, clinically useful and cost-saving compared with routine adenosine testing. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT04674449.

Takotsubo syndrome is a cardiac emergency characterised by left ventricular systolic dysfunction mimicking an acute myocardial infarction. The extent and causes of subsequent morbidity following recovery after an acute takotsubo syndrome episode are unknown. In a case-control study, all patients with takotsubo syndrome (n=620) diagnosed in Scotland between January 2010 and December 2017 were age, sex and geographically matched to contemporaneous general Scottish population control subjects (n=2480) in a ratio of 1:4 and patients with myocardial infarction (n=620) in a ratio of 1:1. Subsequent hospital admissions were obtained from the Public Health Scottish Morbidity Records. Of the total 12,873 hospitalisations, there were 762/1,000 person-years for patients with takotsubo syndrome, 525/1,000 person-years for general Scottish population controls and 757/1,000 person-years for patients with myocardial infarction. In comparison to general population, patients with takotsubo syndrome had higher admissions for cardiovascular causes (hazard ratio 4.26 [95% confidence interval 3.53-5.15]) including myocardial infarction (3.11 [2.11-4.57]), heart failure (4.92 [3.06-7.93]), arrhythmia (3.56 [2.55-4.98]) and stroke (1.88 [1.16-3.03]). There were also excess admissions for mental health (3.74 [2.35-5.94]), pulmonary (3.49 [2.61-4.66]), neurological, infectious, gastro-intestinal, and peripheral vascular disease causes. In comparison to patients with myocardial infarction, patients with takotsubo syndrome had lower admissions for cardiovascular causes (0.58 [0.49-0.70]) including myocardial infarction (0.27 [0.19-0.38]), heart failure (0.55 [0.37-0.83]) and arrhythmia (0.65 [0.47-0.91]) but they were similar for stroke (0.70 [0.41-1.18]); they also had fewer admissions for renal (0.58 [0.41-0.81], infectious (0.75 [0.58-0.97]) and diabetes/endocrine (0.30 [0.13-0.70]) but higher for gastro-intestinal (1.34 [1.02-1.77]) causes. Takotsubo syndrome is associated with substantial morbidity and recurrent hospitalisations highlighting an increased vulnerability, a need for better discharge advice, clinical follow-up and preventative strategies.

Background:Takotsubo syndrome is an increasingly common cardiac emergency with no known evidence-based treatment.Objectives:The purpose of this study was to investigate cardiovascular mortality and medication use after takotsubo syndrome.Methods:In a case-control study, all patients with takotsubo syndrome in Scotland between 2010 and 2017 (n = 620) were age, sex, and geographically matched to individuals in the general population (1:4, n = 2,480) and contemporaneous patients with acute myocardial infarction (1:1, n = 620). Electronic health record data linkage of mortality outcomes and drug prescribing were analyzed using Cox proportional hazard regression models.Results:Of the 3,720 study participants (mean age, 66 years; 91% women), 153 (25%) patients with takotsubo syndrome died over the median of 5.5 years follow-up. This exceeded mortality rates in the general population (N = 374 [15%]; HR: 1.78 [95% CI: 1.48-2.15], P < 0.0001), especially for cardiovascular (HR: 2.47 [95% CI: 1.81-3.39], P < 0.001) but also noncardiovascular (HR: 1.48 [95% CI: 1.16-1.87], P = 0.002) deaths. Mortality rates were lower for patients with takotsubo syndrome than those with myocardial infarction (31%, 195/620; HR: 0.76 [95% CI: 0.62-0.94], P = 0.012), which was attributable to lower rates of cardiovascular (HR: 0.61 [95% CI: 0.44-0.84], P = 0.002) but not non-cardiovascular (HR: 0.92 [95% CI: 0.69-1.23], P = 0.59) deaths. Despite comparable medications use, cardiovascular therapies were consistently associated with better survival in patients with myocardial infarction but not in those with takotsubo syndrome. Diuretic (P = 0.01), anti-inflammatory (P = 0.002), and psychotropic (P < 0.001) therapies were all associated with worse outcomes in patients with takotsubo syndrome.Conclusions:In patients with takotsubo syndrome, cardiovascular mortality is the leading cause of death, and this is not associated with cardiovascular therapy use.

Background: Multivessel coronary disease is common in patients with acute coronary syndromes (ACS). Moreover, incomplete revascularisation has been associated with adverse outcomes in this patient population. Optimising revascularization decisions is therefore clinically important. Methods: Using data from the previously published FAMOUS NSTEMI study, incomplete revascularisation was classified based on the presence of an artery with a residual diameter stenosis of >50% (Core lab). The study protocol for revascularization decisions was an FFR≤0.80 (FFR-group) or a lesion with a diameter stenosis (DS) cut-off >50% (angiography-guided group). Results: Three hundred and fifty patients were randomised (n=176 FFR-guided group, n=174 angiography-guided group), 136 (77.3%) and 151 (86.8%) patients were revascularized by PCI or CABG in the FFR-guided group and angiography-guided groups, respectively (p=0.022). 309 patients had at least one lesion ≥50% severity in an artery amenable to revascularisation. Incomplete revascularisation occurred in 32 (22.7%) of 141 subjects in the FFR-guided group and in 82 (48.8%) of 168 subjects in the angiography-guided group (p<0.0001). In patients treated by PCI, incomplete revascularisation occurred in 24 (19.7%) of 122 subjects in the FFR-guided group and 64 (46%) of 139 subjects in the angiography-guided group (p<0.0001). When a stenosis threshold of ≥70% stenosis severity was used, incomplete revascularisation values remained higher in the angiographic guided arm but did not reach statistical significance (FFR 19.7% vs. Angiography-guided 26.5%, p=0.23). There was no difference in MACE at 12 months between the two groups. Conclusions: In patients with NSTEMI who were randomly assigned to FFR guided management, revascularisation was more often complete than when guided by an angiography-guided strategy.

BackgroundPatients with recent non–ST‐segment elevation myocardial infarction commonly have heterogeneous characteristics that may be challenging to assess clinically. Methods and ResultsWe prospectively studied the diagnostic accuracy of 2 novel (T1, T2 mapping) and 1 established (T2‐weighted short tau inversion recovery [T2W‐STIR]) magnetic resonance imaging methods for imaging the ischemic area at risk and myocardial salvage in 73 patients with non–ST‐segment elevation myocardial infarction (mean age 57±10 years, 78% male) at 3.0‐T magnetic resonance imaging within 6.5±3.5 days of invasive management. The infarct‐related territory was identified independently using a combination of angiographic, ECG, and clinical findings. The presence and extent of infarction was assessed with late gadolinium enhancement imaging (gadobutrol, 0.1 mmol/kg). The extent of acutely injured myocardium was independently assessed with native T1, T2, and T2W‐STIR methods. The mean infarct size was 5.9±8.0% of left ventricular mass. The infarct zone T1 and T2 times were 1323±68 and 57±5 ms, respectively. The diagnostic accuracies of T1 and T2 mapping for identification of the infarct‐related artery were similar (P=0.125), and both were superior to T2W‐STIR (P<0.001). The extent of myocardial injury (percentage of left ventricular volume) estimated with T1 (15.8±10.6%) and T2 maps (16.0±11.8%) was similar (P=0.838) and moderately well correlated (r=0.82, P<0.001). Mean extent of acute injury estimated with T2W‐STIR (7.8±11.6%) was lower than that estimated with T1 (P<0.001) or T2 maps (P<0.001). ConclusionsIn patients with non–ST‐segment elevation myocardial infarction, T1 and T2 magnetic resonance imaging mapping have higher diagnostic performance than T2W‐STIR for identifying the infarct‐related artery. Compared with conventional STIR, T1 and T2 maps have superior value to inform diagnosis and revascularization planning in non–ST‐segment elevation myocardial infarction. Clinical Trial RegistrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT02073422.

In the Fractional flow reserve (FFR) versus angiography in guiding management to optimise outcomes in non-ST elevation myocardial infarction (FAMOUS) clinical trial, FFR was shown to significantly reduce coronary revascularisation, compared to visual interpretation of standard coronary angiography without FFR. We estimated the cost-effectiveness from a UK National Health Service perspective, based on the results of FAMOUS.

Background— The use of fractional flow reserve (FFR) in acute coronary syndromes is controversial. The British Heart Foundation Fractional Flow Reserve Versus Angiography in Guiding Management to Optimize Outcomes in Non-ST-Elevation Myocardial Infarction (FAMOUS-NSTEMI) study (NCT01764334) has recently demonstrated the safety and feasibility of FFR measurement in patients with non–ST-segment–elevation myocardial infarction. We report the findings of the cardiac magnetic resonance (CMR) substudy to assess the diagnostic accuracy of FFR compared with 3.0-T stress CMR perfusion. Methods and Results— One hundred six patients with non–ST-segment–elevation myocardial infarction who had been referred for early invasive management were included from 2 centers. FFR was measured in all major patent epicardial coronary arteries with a visual stenosis estimated at ≥30%, and if percutaneous coronary intervention was performed, an FFR assessment was repeated. Myocardial perfusion was assessed with stress perfusion CMR at 3 T. The mean age was 56.7±9.8 years; 82.6% were men. Mean time from FFR evaluation to CMR was 6.1±3.1 days. The mean±SD left ventricular ejection fraction was 58.2±9.1%. Mean infarct size was 5.4±7.1%, and mean troponin concentration was 5.2±9.2 μg/L. There were 34 fixed and 160 inducible perfusion defects. There was a negative correlation between the number of segments with a perfusion abnormality and FFR ( r =−0.77; P <0.0001). The overall sensitivity, specificity, positive predictive value, and negative predictive value for an FFR of ≤0.8 were 91.4%, 92.2%, 76%, and 97%, respectively. Diagnostic accuracy was 92%. The positive and negative predictive values of FFR for flow-limiting coronary artery disease (FFR≤0.8) in patients with non–ST-segment–elevation myocardial infarction (n=21) who underwent perfusion CMR before invasive angiography were 92% and 93%, respectively. Receiver operating characteristic analysis indicated that the optimal cutoff value of FFR for demonstrating reversible ischemia on CMR was ≤0.805 (area under the receiver operating characteristic curve, 0.94 [0.9–0.99]; P <0.0001). Conclusions— FFR in patients with recent non–ST-segment–elevation myocardial infarction showed high concordance with myocardial perfusion in matched territories as revealed by 3.0-T stress perfusion CMR. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT02073422.

Patients with non-ST elevation myocardial infarction are managed based visual assessment of coronary angiography, which can be inaccurate and subjective. A randomized pilot trial has investigated an alternative approach using physiology-guided management with fractional flow reserve that may optimize outcomes. Objective was to estimate the cost-effectiveness of FFR-guided management vs. coronary angiography. A trial-based economic evaluation was conducted (n=350). We adopted a UK National Health Service perspective. Part I of the analysis used raw, unadjusted costs and QALYs assembled using individual resource use and EQ5D responses from the RCT. Part II used statistical modelling to model the effect pathway of FFR by conditioning total costs and QALYs on the treatment decision (coronary artery bypass graft (CABG), medical therapy and percutaneous coronary intervention (PCI)). Results were then applied to treatment decision distributions following FFR or standard care management. Uncertainty in GLM coefficients, unit cost parameters and sampling were incorporated using bootstrapping and Monte Carlo methods. FFR reduced revascularization by PCI or CABG (OR 0.52; 95%CI: 0.28 – 0.94; p=0.022). Part I: FFR led to a mean cost savings (£8,253 vs. £8,603; difference: –£305 [SD=£519]). Likely drivers of cost savings were length of stay (-£331 [£342]) and index year health events (-£217 [£223]). However, low information size contributed to their large imprecision. Incremental QALYs were comparable (0.811 vs. 0.799; diff: 0.013 [0.023]). Part II: FFR led again to a mean cost savings (£8,328 vs. £8,532; difference: –£204 [£305]) and comparable incremental QALYs (0.801 vs. 0.806; diff: –0.005 [0.004]). The probability of cost-effectiveness remained comparable over common willingness-to-pay (70-75%). Early evidence suggests FFR may be cost saving and comparable in QALYs. However, considerable uncertainty persists. We also prescribe specific design considerations for a future trial, including information size suggestions, follow-up frequency and outcomes to aid modelling/lifetime extrapolation.

Aim We assessed the management and outcomes of non-ST segment elevation myocardial infarction (NSTEMI) patients randomly assigned to fractional flow reserve (FFR)-guided management or angiography-guided standard care. Methods and results We conducted a prospective, multicentre, parallel group, 1 : 1 randomized, controlled trial in 350 NSTEMI patients with ≥1 coronary stenosis ≥30% of the lumen diameter assessed visually (threshold for FFR measurement) (NCT01764334). Enrolment took place in six UK hospitals from October 2011 to May 2013. Fractional flow reserve was disclosed to the operator in the FFR-guided group (n = 176). Fractional flow reserve was measured but not disclosed in the angiography-guided group (n = 174). Fractional flow reserve ≤0.80 was an indication for revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG). The median (IQR) time from the index episode of myocardial ischaemia to angiography was 3 (2, 5) days. For the primary outcome, the proportion of patients treated initially by medical therapy was higher in the FFR-guided group than in the angiography-guided group [40 (22.7%) vs. 23 (13.2%), difference 95% (95% CI: 1.4%, 17.7%), P = 0.022]. Fractional flow reserve disclosure resulted in a change in treatment between medical therapy, PCI or CABG in 38 (21.6%) patients. At 12 months, revascularization remained lower in the FFR-guided group [79.0 vs. 86.8%, difference 7.8% (−0.2%, 15.8%), P = 0.054]. There were no statistically significant differences in health outcomes and quality of life between the groups. Conclusion In NSTEMI patients, angiography-guided management was associated with higher rates of coronary revascularization compared with FFR-guided management. A larger trial is necessary to assess health outcomes and cost-effectiveness.

An economic model was developed to compare the medical resource cost and health outcome effects of physiology-guided management with FFR compared with standard angiography-guided management in patients with non-ST elevation myocardial infarction based on participants British Heart Foundation FAMOUS-

Background:Coronary microcirculatory function may be disturbed in patients with a recent acute coronary syndrome. Myocardial fractional flow reserve (FFR) is a guidewire-derived index of coronary stenosis severity that was validated in patients with stable symptoms. We aimed to assess the diagnostic accuracy of FFR in patients with a recent non-ST segment myocardial infarction (NSTEMI) when compared with 3T stress perfusion MRI.Methods:106 patients with NSTEMI who had been referred for early invasive management guided by coronary angiography were included. FFR was measured in all major patent epicardial coronary arteries with a visual stenosis estimated at≥ 30%. In addition, where clinically appropriate, an FFR assessment following PCI was also performed. Myocardial perfusion was subsequently assessed non-invasively with stress MRI at 3T (Siemens MAGNETOM Verio). MRI provided the …

Objectives The aim of this study was to assess whether deferred stenting might reduce no-reflow and salvage myocardium in primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).Background No-reflow is associated with adverse outcomes in STEMI.Methods This was a prospective, single-center, randomized, controlled, proof-of-concept trial in reperfused STEMI patients with >= 1 risk factors for no-reflow. Randomization was to deferred stenting with an intention-to-stent 4 to 16 h later or conventional treatment with immediate stenting. The primary outcome was the incidence of no-/slow-reflow (Thrombolysis In Myocardial Infarction <= 2). Cardiac magnetic resonance imaging was performed 2 days and 6 months after myocardial infarction. Myocardial salvage was the final infarct size indexed to the initial area at risk.Results Of 411 STEMI patients (March 11, 2012 to November 21, 2012), 101 patients (mean age, 60 years; 69% male) were randomized (52 to the deferred stenting group, 49 to the immediate stenting). The median (interquartile range [IQR]) time to the second procedure in the deferred stenting group was 9 h (IQR: 6 to 12 h). Fewer patients in the deferred stenting group had no-/slow-reflow (14 [29%] vs. 3 [6%]; p = 0.006), no reflow (7 [14%] vs. 1 [2%]; p = 0.052) and intraprocedural thrombotic events (16 [33%] vs. 5 [10%]; p 0.010). Thrombolysis In Myocardial Infarction coronary flow grades at the end of PCI were higher in the deferred stenting group (p = 0.018). Recurrent STEMI occurred in 2 patients in the deferred stenting group before the second procedure. Myocardial salvage index at 6 months was greater in the deferred stenting group (68 [IQR: 54% to 82%] vs. 56 [IQR: 31% to 72%]; p = 0.031].Conclusions In high-risk STEMI patients, deferred stenting in primary PCI reduced no-reflow and increased myocardial salvage. (Deferred Stent Trial in STEMI; NCT01717573) (c) 2014 by the American College of Cardiology Foundation

Background In patients with acute non-ST-elevation myocardial infarction (NSTEMI), coronary arteriography is usually recommended; but visual interpretation of the angiogram is subjective. We hypothesized that functional assessment of coronary stenosis severity with a pressure-sensitive guide wire (fractional flow reserve [FFR]) would have additive diagnostic, clinical, and health economic utility as compared with angiography-guided standard care.Methods and design Aprospectivemulticenter parallel-group 1:1 randomized controlled superiority trial in 350 NSTEMI patients with >= 1 coronary stenosis >= 30% severity (threshold for FFR measurement) will be conducted. Patients will be randomized immediately after coronary angiography to the FFR-guided group or angiography-guided group. All patients will then undergo FFR measurement in all vessels with a coronary stenosis >= 30% severity including culprit and nonculprit lesions. Fractional flow reserve will be disclosed to guide treatment in the FFR-guided group but not disclosed in the "angiography-guided" group. In the FFR-guided group, an FFR <= 0.80 will be an indication for revascularization by percutaneous coronary intervention or coronary artery bypass surgery, as appropriate. The primary outcome is the between-group difference in the proportion of patients allocated to medical management only compared with revascularization. Secondary outcomes include the occurrence of cardiac death or hospitalization for myocardial infarction or heart failure, quality of life, and health care costs. The minimum and average follow-up periods for the primary analysis are 6 and 18 months, respectively.Conclusions Our developmental clinical trial will address the feasibility of FFR measurement in NSTEMI and the influence of FFR disclosure on treatment decisions and health and economic outcomes.

Royal Medico-Chirurgical Society of Glasgow Research Prize Evening, 7 March 2013 The prize winners were as follows: Best oral presentation: Dr David Carrick Best poster presentation bya trainee:DrCatrionaBrown Best poster presentation by a medical student: Mr Mark White Aberrant NF-kappa B expression in autism spectrum condition: a mechanism for neuroinflammation AMH Young, EC Campbell, S Lynch, MH Dunn SJ, J Powis and J Suckling School of Clinical Medicine, University of Cambridge, Addenbrookes Hospital, UK Bute Medical School, University of St. Andrews, UK Department of Physics & Astronomy, University of St. Andrews, Fife, UK Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, UK

Treatment decisions in the invasive management of patients with non-ST elevation myocardial infarction (NSTEMI) are usually made based on visual interpretation of the coronary angiogram. The relationships between coronary stenosis severity and myocardial fractional flow reserve (FFR) in this setting

Background— The use of fractional flow reserve in patients with non–ST-segment–elevation myocardial infarction (NSTEMI) is a controversial issue. We undertook a study to assess the vasodilatory capacity of the coronary microcirculation in patients with NSTEMI when compared with a model of preserved microcirculation (stable angina [SA] cohort: culprit and nonculprit vessel) and acute microcirculatory dysfunction (ST-segment–elevation myocardial infarction [STEMI] cohort). We hypothesized that the vasodilatory response of the microcirculation would be preserved in NSTEMI. Methods and Results— A total of 140 patients undergoing single vessel percutaneous coronary intervention were included: 50 stable angina, 50 NSTEMI, and 40 STEMI. The index of microvascular resistance (IMR), fractional flow reserve, and coronary flow reserve were measured before stenting in the culprit vessel and in an angiographically normal nonculprit vessel in patients with SA. The resistive reserve ratio, a measure of the vasodilatory capacity of the microcirculation and calculated using the equation: baseline resistance index ( Tmn Base × Pa Base [ Pd Base – Pw / Pa Base – Pw ])–IMR/IMR, where Tmn Base referred to nonhyperemic transit time; Pa Base and Pd Base , the nonhyperemic aortic and distal coronary pressures, respectively; and Pw referred to the coronary wedge pressure, was also measured. Troponin was also measured ≤24 hours after percutaneous coronary intervention. The resistive reserve ratio was significantly lower in the STEMI patients compared with the stable angina patients both culprit and nonculprit vessel (STEMI, 1.7 versus SA culprit, 2.8; P ≤0.001 and SA nonculprit, 2.9; P <0.0001) and compared with NSTEMI patients (NSTEMI, 2.46; P ≤0.001). The resistive reserve ratio was similar in stable angina and NSTEMI patients ( P =0.6). IMR was significantly higher pre-PCI in STEMI compared with SA and NSTEMI (IMR STEMI, 36.51 versus IMR NSTEMI, 22.73 [ P =0.01] versus IMR SA, 18.26 [ P <0.0001]). However, there was no significant difference in IMR pre-PCI between NSTEMI and SA (IMR NSTEMI, 22.73; IMR SA, 18.26 [ P =0.1]). Conclusions— The vasodilatory capacity of the microcirculation is preserved in selected patients with NSTEMI. The clinical use of fractional flow reserve in the culprit vessel may be preserved in selected patents with NSTEMI.

Introduction In primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI), no-reflow after stenting may cause heart failure acutely and in the longer term. Currently there are no evidence-based treatments for no-reflow. We hypothesised that after initial myocardial reperfusion, deferring stent implantation for a limited period of time might reduce no-reflow and its sequelae compared to usual care with immediate stenting. Methods A prospective randomised controlled trial in consecutive STEMI patients (NCT01717573). Patients with risk factors for no-reflow (eg, occluded artery (TIMI 0/1), heavy thrombus burden (TIMI 2+ thrombus grade)) were eligible if TIMI 3 coronary flow had been established by initial aspiration thrombectomy and/or balloon angioplasty. Randomisation was performed electronically to deferred stenting (4–16 h later) or usual care with immediate stenting. Deferred patients received intravenous tirofiban and subcutaneous enoxaparin during the period between randomisation and stenting. All patients received oral dual antiplatelet therapy. The primary end-point was the incidence of no-reflow, defined as the occurrence of TIMI 0/1 flow post stenting. Contrast-enhanced cardiac MRI was performed 2 days post-MI and all patients had prospective follow-up. The angiograms and clinical events were independently adjudicated. Results Of 451 consecutive STEMI patients treated in our centre (11 March–22 November 2012), 101 patients (mean±SD age 60±12 years; 69% male, 13% diabetes, 7% previous MI) were randomised (n=52 to deferred stenting, n=49 immediate stenting). The clinical characteristics were similar in each group. In the deferred stent group, the median (IQR) time to deferred stenting was 8 (6, 11) hours. Compared with usual care with immediate stenting, no-reflow was significantly less frequent in the deferred stenting group: 0.0% versus 10% (p=0.005). Intra-procedural thrombotic events (IPTEs) were also less frequent with deferred stenting: 14% versus 41% (p=0.003). Contrast-enhanced MRI disclosed microvascular obstruction in 59% of patients in the immediate stenting group and 44% in the deferred stenting group (p=0.36). Killip class III heart failure occurred in two patients in the deferred stent group and in one patient in the immediately stented group. Recurrent MI <6h from randomisation occurred in two patients in the deferred group (1 culprit lesion and 1 non-culprit lesion) and no patients in the immediate stenting group. Conclusions For the first time we have found that a strategy of deferred stenting in selected patients reduced no-reflow and IPTEs in primary PCI. Our intervention is pragmatic and potentially widely applicable. Our results support the rationale for a multicentre trial to assess the safety and cost-effectiveness of deferred stenting in primary PCI.

This case illustrates a novel and innovative method of retrieving a kinked guiding catheter in transradial intervention without the need for vascular snare.