Clinical outcomes of left ventricular unloading with microaxial flow pump Impella during venoarterial extracorporeal membrane oxygenation (VA-ECMO): a systematic review and updated meta-analysis

Background

Whether the addition of percutaneous microaxial flow pump Impella to venoarterial extracorporeal membrane oxygenation (VA-ECMO) as left ventricle unloading strategy is effective in improving outcomes compared to VA-ECMO alone is still to be proved.

Purpose

Aim of this systematic review and meta-analysis was to assess whether patients with refractory cardiogenic shock treated with IMPELLA in addition to VA-ECMO (ECMELLA) versus ECMO alone may benefit a reduction in early mortality and to assess whether this strategy may result in an increased rate of complications.

Methods

For this systematic review and meta-analysis, from Dec 2021 to Jan 2022, we searched Scopus, MEDLINE (with PubMed interface) and the Cochrane Central Register of Controlled Trials for randomised controlled trials and observational studies published in any language comparing the use of ECMELLA versus ECMO alone in patients with acute refractory CS (with or without cardiac arrest). Two independent investigators screened titles and abstracts for eligibility, extracted the data, and assessed risk of bias. Risk ratios (RRs) and 95% CIs were calculated with random-effects or fixed-effect models according to the estimated heterogeneity among studies assessed by the I2 index. Primary efficacy endpoint was trial-defined early mortality (in hospital or 30-day mortality). Safety endpoints were major bleeding, the need for renal replacement therapy, hemolysis, severe infections/sepsis and limb ischemia. This study is registered with PROSPERO (CRD42022292517).

Results

2061 potentially relevant articles were screened. Our analysis included six retrospective studies with data for 1457 patients. Compared with ECMO alone, ECMELLA was associated with a non-significant reduction in early mortality (RR 0.87, 95% CI 0.72–1.06, p=0.17; Figure 1) and in a significant increase of major bleeding (RR 1.45, 95% CI 1.10–1.91, p=0.009), need for renal replacement therapy (RR 1.70, 95% CI 1.16–2.48, p=0.0008), hemolysis (RR 2.22, 95% CI 1.39–3.56, p=0.005) and limb ischemia (RR 1.61, 95% CI 1.20–2.16, p=0.001). No significant differences were observed in the incidence of severe infections/sepsis between the two groups (RR 1.23, 95% CI 0.97–1.58, p=0.09). (Figure 2)

Conclusions

The results of this meta-analysis showed that ECMELLA compared to ECMO alone did not significantly reduce early mortality and that, conversely, it resulted in a significantly increased risk of several complication (major bleeding, hemolysis, limb ischemia and renal replacement therapy). This study highlights that, if the benefit of left ventricle unloading with Impella during ECMO in CS shock is uncertain and probably limited to only selected patients, it surely increases the risk of some complications, therefore caution is needed in choosing such a strategy.

Funding Acknowledgement

Type of funding sources: None.

Ticagrelor and preconditioning in patients with stable coronary artery disease (TAPER-S): a randomized pilot clinical trial

Background

Ticagrelor is a reversibly binding, direct-acting, oral, P₂Y₁₂ antagonist used for the prevention of atherothrombotic events in patients with coronary artery disease (CAD). Ticagrelor blocks adenosine reuptake through the inhibition of equilibrative nucleoside transporter 1 (ENT-1) on erythrocytes and platelets, thereby facilitating adenosine-induced physiological responses such as an increase in coronary blood flow velocity. Meanwhile, adenosine plays an important role in triggering ischemic preconditioning through the activation of the A1 receptor. Therefore, an increase in ticagrelor-enhanced adenosine bioavailability may confer beneficial effects through mechanisms related to preconditioning activation and improvement of coronary microvascular dysfunction.

Methods

To determine whether ticagrelor can trigger ischemic preconditioning and influence microvascular function, we designed this prospective, open-label, pilot study that enrolled patients with stable multivessel CAD requiring staged, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI). Participants will be randomized in 1:1 ratios either to ticagrelor (loading dose (LD) 180 mg, maintenance dose (MD) 90 mg bid) or to clopidogrel (LD 600 mg, MD 75 mg) from 3 to 1 days before the scheduled PCI. The PCI operators will be blinded to the randomization arm. The primary endpoint is the delta (difference) between ST segment elevations (in millimeters, mm) as assessed by intracoronary electrocardiogram (ECG) during the two-step sequential coronary balloon inflation in the culprit vessel. Secondary endpoints are 1) changes in coronary flow reserve (CFR), index of microvascular resistance (IMR), and FFR measured in the culprit vessel and reference vessel at the end of PCI, and 2) angina score during inflations. This study started in 2018 with the aim of enrolling 100 patients. Based on the rate of negative FFR up to 30% and a drop-out rate up to 10%, we expect to detect an absolute difference of 4 mm among the study arms in the mean change of ST elevation following repeated balloon inflations. All study procedures were reviewed and approved by the Ethical Committee of the Catholic University of Sacred Heart.

Discussion

Ticagrelor might improve ischemia tolerance and microvascular function compared to clopidogrel, and these effects might translate to better long-term clinical outcomes.

Trial registration

EudraCT No. 2016–004746-28. No. NCT02701140. 

Trial status

Information provided in this manuscript refers to the definitive version (n. 3.0) of the study protocol, dated 31 October 2017, and includes all protocol amendments. Recruitment started on 18 September 2018 and is currently ongoing. The enrollment is expected to be completed by the end of 2019.

Trial sponsor

Fondazione Policlinico Universitario A. Gemelli – Roma, Polo di Scienze Cardiovascolari e Toraciche, Largo Agostino Gemelli 8, 00168 Rome, Italy.

100Culprit plaque morphology in patients with and without preinfarction angina: an optical coherence tomography imaging study

Background

The relation between culprit plaque morphology and the clinical presentation of an acute myocardial infarction (AMI) has not been examined in detail.

Purpose

To study the culprit plaque morphology in patients with AMI with or without preinfarction angina using optical coherence tomography (OCT) imaging.

Methods

A total of 102 patients with AMI (32 STEMI, 70 NSTEMI) who underwent OCT imaging before percutaneous coronary intervention were enrolled. Patients were classified as: i) having either intermittent chest pain in the six hours preceding the final episode of pain, or unstable angina (or both) in the week preceding AMI (preinfarction angina group); or ii) having a single episode of chest pain without unstable symptoms in the preceding week (no preinfarction angina group). Culprit plaque was classified as plaque rupture (PR) or intact fibrous cap (IFC), as previously described. Prati thrombus score was calculated, and the prevalence of calcification, neovascularization, and OCT-defined macrophage accumulation was assessed.

Results

Patients with preinfarction angina showed a significantly higher prevalence of IFC than PR, while those without preinfarction angina showed a significantly higher prevalence of PR than IFC (Figure). PR in patients with preinfarction angina were more frequently associated with macrophage accumulation, while those in patients without preinfarction angina were not (Figure). White thrombus tended to be more frequent in patients with preinfarction angina than in those without (85.7% vs. 63.6%, p=0.097), and Prati thrombus score tended to be lower [22.0 (15.8–30.3) vs. 38.5 (12.8–67.5), p=0.145]. Calcifications were significantly less frequent in patients with preinfarction angina than in those without (22.0% vs. 40.4%, p=0.045), while neovascularization tended to be more frequent (58.0% vs. 42.3%, p=0.113).

Conclusions

Patients with preinfarction angina have a distinct culprit plaque phenotype, frequently characterized by IFC and a relatively lower thrombotic burden, probably reflecting a prevalence of reparative mechanisms and spontaneous thrombolytic activity in these patients.