A randomised controlled trial of deferred stenting versus immediate stenting to prevent no-reflow in acute ST-elevation myocardial infarction

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 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.