Long-term outcome after thrombus aspiration in non-ST-elevation myocardial infarction: results from the TATORT-NSTEMI trial : Thrombus aspiration in acute myocardial infarction

Propensity score analysis of very long-term outcome after coronary thrombus aspiration in acute myocardial infarction

BACKGROUND

The long-term prognostic impact of thrombus aspiration (TA) in acute myocardial infarction (AMI) is unclear.

AIM

To assess the long-term prognostic impact of TA in AMI.

METHODS

Data were obtained from three nationwide French surveys (FAST-MI 2005, 2010 and 2015) including consecutive patients with AMI. Long-term death rate (up to 10 years) was assessed according to use of TA in patients with AMI treated with percutaneous coronary intervention (PCI).

RESULTS

TA was used in 1781/9654 patients (18%; 2005, 7%; 2010, 27%; 2015, 18%), including 1546 (86.8%) with ST-segment elevation myocardial infarction. Patients who had TA were younger (61 vs. 65 years; P<0.001), mostly men (81 vs. 74%; P<0.001) and their culprit lesion was more often on the right coronary artery (40 vs. 31%; P<0.001). Crude very long-term mortality was lower with TA (25.0 vs. 32.5%; crude hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.68-0.82; P<0.001). Adjusting on a propensity score (PS) for getting TA, very long-term mortality did not differ (HR 1.03, 95% CI 0.89-1.20; P=0.67). In-hospital stroke was more frequent with TA (0.7 vs. 0.4%; P=0.04). After PS matching (two cohorts, 1430 patients in each), very long-term mortality was similar in the two PS-matched cohorts (HR 1.02, 95% CI 0.87-1.19; P=0.84). In patients with a high thrombus burden, the adjusted HR for very long-term mortality was 0.76 (95% CI 0.59-0.98; P=0.03) in favour of TA.

CONCLUSIONS

These routine-practice data show that TA use increased until 2010 and declined thereafter, in keeping with international guidelines. In the overall population of patients with AMI who underwent PCI, TA had no effect on long-term survival. In those with a high thrombus burden, TA was associated with improved long-term survival.

The immunopathology of coronary microembolization and the underlying inflammopathophysiological mechanisms

In coronary microembolization, inflammatory cell infiltration, patchy necrosis, and extensive intra-myocardial hemorrhage are dominant, which induce myocardial dysfunction with clinical symptoms of chronic ischemic cardiomyopathy. Microembolization can lead to obstruction of the coronary microvessels and result in the micro-infarction of the heart. The inflammation and elevated expression of the tumor necrosis factor in cardiomyocytes and the activation of extracellular ERK are involved in initiating the inflammatory response mechanism. The PI3K/Akt signaling pathway is the enriched pathway, and for controlling, inhibition of PI3K/Akt is necessary. Furthermore, the release of cytokines and the activation of inflammasomes contribute to the enhancement of vascular permeability, which results in edema within the myocardium. The immune response and inflammation represent the primary triggers in this process. The ability to control immune response and inflammation reactions may lead to the development of new therapies for microembolization.

Coronary microvascular obstruction and dysfunction in patients with acute myocardial infarction

Despite prompt epicardial recanalization in patients presenting with ST-segment elevation myocardial infarction (STEMI), coronary microvascular obstruction and dysfunction (CMVO) is still fairly common and is associated with poor prognosis. Various pharmacological and mechanical strategies to treat CMVO have been proposed, but the positive results reported in preclinical and small proof-of-concept studies have not translated into benefits in large clinical trials conducted in the modern treatment setting of patients with STEMI. Therefore, the optimal management of these patients remains a topic of debate. In this Review, we appraise the pathophysiological mechanisms of CMVO, explore the evidence and provide future perspectives on strategies to be implemented to reduce the incidence of CMVO and improve prognosis in patients with STEMI.

Effect of Coronary Thrombus Aspiration in Non ST Elevation Acute Coronary Syndrome Patients on Three-Year Survival- Does it add any Benefit?

We assessed the effect of thrombus aspiration (TA) during percutaneous coronary intervention (PCI) on in-hospital and 3-year mortality in consecutive non-ST segment elevation myocardial infarction (n = 189) and unstable angina pectoris (n = 148) patients (n = 337) between 2011 and 2016. In total, 153 patients (45.4%) underwent TA. The number of patients with postoperative thrombolysis in terms of myocardial infarction grade 3 blood flow (P < .001) and myocardial blush grade 3 (P < .001) were significantly higher in all TA groups. At 6-, 12- and 24-month post-PCI, the mean left ventricular ejection fraction was significantly higher in the all TA groups versus the stand alone PCI group (P < .001). Thrombus aspiration was associated with a significant improvement both in epicardial flow, myocardial perfusion and left ventricular ejection fraction. Thrombus aspiration during PCI in all acute coronary syndrome (except ST segment elevation) patients was associated with better survival compared with stand alone PCI group at 3-year follow-up (P = .019).

A fresh look at coronary microembolization

Mechanical stress from haemodynamic perturbations or interventional manipulation of epicardial coronary atherosclerotic plaques with inflammatory destabilization can release particulate debris, thrombotic material and soluble substances into the coronary circulation. The physical material obstructs the coronary microcirculation, whereas the soluble substances induce endothelial dysfunction and facilitate vasoconstriction. Coronary microvascular obstruction and dysfunction result in patchy microinfarcts accompanied by an inflammatory reaction, both of which contribute to progressive myocardial contractile dysfunction. In clinical studies, the benefit of protection devices to retrieve atherothrombotic debris during percutaneous coronary interventions has been modest, and the treatment of microembolization has mostly relied on antiplatelet and vasodilator agents. The past 25 years have witnessed a relative proportional increase in non-ST-segment elevation myocardial infarction in the presentation of acute coronary syndromes. An associated increase in the incidence of plaque erosion rather than rupture has also been recognized as a key mechanism in the past decade. We propose that coronary microembolization is a decisive link between plaque erosion at the culprit lesion and the manifestation of non-ST-segment elevation myocardial infarction. In this Review, we characterize the features and mechanisms of coronary microembolization and discuss the clinical trials of drugs and devices for prevention and treatment.

Myocardial salvage is increased after sympathetic renal denervation in a pig model of acute infarction

RATIONALE

Despite advances in treatment of acute myocardial infarction (AMI), many patients suffer significant myocardial damage with cardiac dysfunction. Sympathetic renal denervation (RD) may reduce adrenergic activation following AMI.

OBJECTIVE

To investigate the potential role of RD limiting myocardial damage and remodeling when performed immediately after AMI.

METHODS AND RESULTS

Sixteen farm pigs underwent 90 min left anterior descending artery balloon occlusion. Eight pigs underwent RD immediately after reperfusion. LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance 5 and 30 days after AMI. ¹²³I-MIBG scintigraphy was performed 31 days after AMI to image myocardial sympathetic innervation. Heart norepinephrine was quantified (from necrotic, border and remote zone). RD and control did not differ in myocardium at risk extent (59 ± 9 vs 55 ± 11% of LV mass) at 5 days. At 30 days CMR, RD pigs had smaller necrotic areas than control as assessed by gadolinium delay enhancement (18 ± 7 vs 30 ± 12% of LV mass, p = 0.021) resulting in improved myocardial salvage index (60 ± 11 vs 44 ± 27%, p < 0.001). RD pigs had higher cardiac output (3.7 ± 0.8 vs 2.66 ± 0.7 L/min, p < 0.001) and lower LV end diastolic volume (98 ± 16 vs 113 ± 31 ml, p = 0.041). ¹²³I-MIBG defect extension was smaller in RD than control (60 ± 28 vs 78 ± 17%, p < 0.05) with significant reduction in the difference between innervation and perfusion defects (25 ± 12 vs 36 ± 30%, p = 0.013). NE content from necrotic area (238; IQR 464 vs 2546; IQR 1727 ng/g in RD and control, respectively, p < 0.001) and from border zone (295; IQR 264 vs 837; IQR 207 in RD and control, respectively, p = 0.031) was significantly lower in RD than control.

CONCLUSIONS

RD results in increased myocardial salvage and better cardiac function, when performed immediately after AMI. Reduction of sympathetic activation with preservation of cardiac sympathetic functionality warranted by RD may sustain these effects.