Influence of microvascular dysfunction on regional myocardial deformation post-acute myocardial infarction: insights from a novel angiographic index for assessing myocardial tissue-level reperfusion

Prognostic value of angiographic microvascular resistance in patients with ST-segment elevation myocardial infarction

BACKGROUND

The Angiographic Microvascular Resistance (AMR), derived from a solitary angiographic view, has emerged as a viable substitute for the Index of Microcirculatory Resistance (IMR). However, the prognostic significance in ST-Segment Elevation Myocardial Infarction (STEMI) patients is yet to be established. This research endeavors to explore the prognostic capabilities of AMR in patients diagnosed with STEMI.

METHODS

In this single-center, retrospective study, 232 patients diagnosed with STEMI who received primary Percutaneous Coronary Intervention (PCI) were recruited from January 1, 2018, to June 30, 2022. Utilizing the maximally selected log-rank statistics analysis, participants were divided into two cohorts according to an AMR threshold of 2.55 mmHg*s/cm. The endpoint evaluated was a composite of all-cause mortality or hospital readmission due to heart failure.

RESULTS

At a median follow-up of 1.74 (1.07, 3.65) years, the composite endpoint event was observed in 28 patients within the higher AMR group and 8 patients within the lower AMR group. The higher AMR group showed a significantly higher risk for composite outcome compared to those within the low-AMR group (HRadj: 3.33; 95% CI 1.30‒8.52; p = 0.03). AMR ≥ 2.55 mmHg*s/cm was an independent predictor of the composite endpoint (HR = 2.33; 95% CI 1.04‒5.21; p = 0.04). Furthermore, a nomogram containing age, sex, left ventricle ejection fraction, post-PCI Quantitative Flow Ratio (QFR), and AMR was developed and indicated a poorer prognosis in the high-risk group for STEMI patients at 3 years. (HR=4.60; 95% CI 1.91‒11.07; p < 0.01).

CONCLUSIONS

AMR measured after PCI can predict the risk of all-cause death or readmission for heart failure in patients with STEMI. AMR-involved nomograms improved predictive performance over variables alone.

Effect of intra-coronary administration of tirofiban through aspiration catheter on patients over 60 years with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

The aim of this study was to compare the efficacy and safety of 2 approaches for intra-coronary administration of tirofiban (aspiration catheter versus guiding catheter) in patients over 60 years of age undergoing percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). It has been suggested that the administration of tirofiban by intra-coronary injection could promote drug absorption in the diseased region and enhance the inhibition of platelet aggregation, decreasing bleeding rates, but little is known about the comparative efficiency and safety of using guiding catheter versus aspiration catheter for delivery.Eighty-nine patients over 60 years of age with STEMI undergoing PCI were randomly divided into 2 groups according to the injection route for intracoronary administration of tirofiban [guiding catheter (n = 41) and aspiration catheter (n = 48)]. Baseline features, epicardial and myocardial perfusion, major adverse cardiac and cerebrovascular events (MACCEs), and bleeding rate were compared.No differences in age, gender, and history of hypertension, hypercholesterolemia, diabetes, and so on were observed (P > .05). The patients in the aspiration catheter group generally had a higher incidence of cerebral vascular disease. Compared with those in the guiding catheter group, patients in the aspiration catheter group obtained more favorable myocardial perfusion (P < .05). In-hospital and at 3-month and 6-month follow-ups, the MACCE rate and frequency of bleeding events were similar between the 2 groups (P > .05).Intra-coronary delivery of tirofiban through aspiration catheter led to better myocardial perfusion in STEMI patients over 60 years of age undergoing PCI compared with intra-coronary injection of tirofiban through guiding catheter. The 2 delivery routes were associated with similar rates of MACCEs and bleeding events.

Efficacy and Safety of a Pharmaco-Invasive Strategy With Half-Dose Alteplase Versus Primary Angioplasty in ST-Segment-Elevation Myocardial Infarction: EARLY-MYO Trial (Early Routine Catheterization After Alteplase Fibrinolysis Versus Primary PCI in Acute ST-Segment-Elevation Myocardial Infarction)

BACKGROUND

Timely primary percutaneous coronary intervention (PPCI) cannot be offered to all patients with ST-segment-elevation myocardial infarction (STEMI). Pharmaco-invasive (PhI) strategy has been proposed as a valuable alternative for eligible patients with STEMI. We conducted a randomized study to compare the efficacy and safety of a PhI strategy with half-dose fibrinolytic regimen versus PPCI in patients with STEMI.

METHODS

The EARLY-MYO trial (Early Routine Catheterization After Alteplase Fibrinolysis Versus Primary PCI in Acute ST-Segment-Elevation Myocardial Infarction) was an investigator-initiated, prospective, multicenter, randomized, noninferiority trial comparing a PhI strategy with half-dose alteplase versus PPCI in patients with STEMI 18 to 75 years of age presenting ≤6 hours after symptom onset but with an expected PCI-related delay. The primary end point of the study was complete epicardial and myocardial reperfusion after PCI, defined as thrombolysis in myocardial infarction flow grade 3, thrombolysis in myocardial infarction myocardial perfusion grade 3, and ST-segment resolution ≥70%. We also measured infarct size and left ventricular ejection fraction with cardiac magnetic resonance and recorded 30-day clinical and safety outcomes.

RESULTS

A total of 344 patients from 7 centers were randomized to PhI (n=171) or PPCI (n=173). PhI was noninferior (and even superior) to PPCI for the primary end point (34.2% versus 22.8%, P_{noninferiority}<0.05, P_superiority=0.022), with no significant differences in the frequency of the individual components of the combined end point: thrombolysis in myocardial infarction flow 3 (91.3% versus 89.2%, P=0.580), thrombolysis in myocardial infarction myocardial perfusion grade 3 (65.8% versus 62.9%, P=0.730), and ST-segment resolution ≥70% (50.9% versus 45.5%, P=0.377). Infarct size (23.3%±11.3% versus 25.8%±13.7%, P=0.101) and left ventricular ejection fraction (52.2%±11.0% versus 51.4%±12.0%, P=0.562) were similar in both groups. No significant differences occurred in 30-day rates of total death (0.6% versus 1.2%, P=1.0), reinfarction (0.6% versus 0.6%, P=1.0), heart failure (13.5% versus 16.2%, P=0.545), major bleeding events (0.6% versus 0%, P=0.497), or intracranial hemorrhage (0% versus 0%), but minor bleeding (26.9% versus 11.0%, P<0.001) was observed more often in the PhI group.

CONCLUSIONS

For patients with STEMI presenting ≤6 hours after symptom onset and with an expected PCI-related delay, a PhI strategy with half-dose alteplase and timely PCI offers more complete epicardial and myocardial reperfusion when compared with PPCI. Adequately powered trials with this reperfusion strategy to assess clinical and safety outcomes are warranted.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01930682.

Prognostic nutritional index predicts clinical outcome in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

We aimed to investigate whether the prognostic nutritional index (PNI), a combined nutritional-inflammatory score based on serum albumin levels and lymphocyte count, was associated with mortality in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). From September 2011 to November 2014, 309 consecutive patients with STEMI undergoing pPCI were prospectively enrolled. Patients with a combined score of albumin (g/L) + 5 × total lymphocyte count × 10⁹/L ≥ 45 or <45 were assigned a PNI score of 0 or 1, respectively. Of the 309 STEMI patients, 24 (7.74%) died in the hospital, and 15 (4.83%) died during long-term follow-up (median follow-up time, 19.5 [3–36] months). Compared to patients with a PNI of 0, patients with a PNI of 1 had significantly higher in-hospital (14.2% vs. 3.7%; P < 0.001) and long-term follow-up (21.7% vs. 6.9%, P < 0.001) mortality rates. PNI (1/0, HR, 2.414; 95% CI, 1.016 to 5.736; P = 0.046) was a significant independent predictor of mortality in patients with STEMI undergoing pPCI. Moreover, cumulative survival was significantly lower for patients with a PNI of 1 compared to patients with a PNI of 0 (78.3% vs. 93.1%, log-rank P < 0.001). PNI appears useful for the risk stratification of STEMI patients undergoing pPCI.