Development of a simple prediction model for mechanical complication in ST-segment elevation myocardial infarction patients after primary percutaneous coronary intervention

Mechanical complication (MC) is a rare but serious complication in patients with ST-segment elevation myocardial infarction (STEMI). Although several risk factors for MC have been reported, a prediction model for MC has not been established. This study aimed to develop a simple prediction model for MC after STEMI. We included 1717 patients with STEMI who underwent primary percutaneous coronary intervention (PCI). Of 1717 patients, 45 MCs occurred after primary PCI. Prespecified predictors were determined to develop a tentative prediction model for MC using multivariable regression analysis. Then, a simple prediction model for MC was generated. Age ≥ 70, Killip class ≥ 2, white blood cell ≥ 10,000/µl, and onset-to-visit time ≥ 8 h were included in a simple prediction model as "point 1" risk score, whereas initial thrombolysis in myocardial infarction (TIMI) flow grade ≤ 1 and final TIMI flow grade ≤ 2 were included as "point 2" risk score. The simple prediction model for MC showed good discrimination with the optimism-corrected area under the receiver-operating characteristic curve of 0.850 (95% CI: 0.798-0.902). The predicted probability for MC was 0-2% in patients with 0-4 points of risk score, whereas that was 6-50% in patients with 5-8 points. In conclusion, we developed a simple prediction model for MC. We may be able to predict the probability for MC by this simple prediction model.

The diagonal branches and outcomes in patients with anterior ST- elevation myocardial infarction

BACKGROUND

The management of diagonal branch (D) occlusion is still controversary. The association between the flow loss of D and the prognosis remains unclear. We aim to detect the impact of D flow on cardiac function and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction (STEMI).

METHODS

Patients with anterior STEMI undergoing primary percutaneous coronary intervention (PCI) at our clinic between October 2015 and October 2018were reviewed. Anterior STEMI due to left anterior descending artery (LAD) occlusion with or without loss of the main D flow (TIMI grade 0-1 or 2-3) was enrolled in the analysis. The short- and long-term incidence of major adverse cardiac events (MACEs, a composite of all-cause death, target vessel revascularization and reinfarction) and left ventricular ejection fraction (LVEF) were analyzed.

RESULTS

A total of 392 patients (mean age of 63.9 years) with anterior STEMI treated with primary PCI was enrolled in the study. They were divided into two groups, loss (TIMI grade 0-1, n = 69) and no loss (TIMI grade2-3, n = 323) of D flow, before primary PCI. Compared with the group without loss of D flow, the group with loss of D flow showed a lower LVEF post PCI (41.0% vs. 48.8%, p = 0.003). Meanwhile, loss of D flow resulted in the higher in-hospital, one-month, and 18-month incidence of MACEs, especially in all-cause mortality (all p < 0.05). Landmark analysis further indicated that the significant differences in 18-month outcomes between the two groups mainly resulted from the differences during the hospitalization. In addition, multivariate Cox proportional hazards analysis found that D flow loss before primary PCI was independent factor predicting short- and long-term outcomes in patients with anterior STEMI.

CONCLUSION

Loss of the main D flow in anterior STEMI patients was independently associated with the higher in-hospital incidences of MACEs and all-cause death as well as the lower LVEF.

An unexpected electrocardiogram sign of subacute left ventricular free wall rupture: Its early awareness may be lifesaving

BACKGROUND

Post-infarct left ventricular free wall rupture (LVFWR) is not always an immediately catastrophic complication. The rupture can be subacute, allowing time for diagnosis and intervention. Accordingly, early recognition of the entity may be lifesaving.

METHODS

We present an electrocardiogram (ECG) change pattern in two cases, which was erroneously attributed to ischemia. Two women in their 80s were admitted to our institute after experiencing the sudden onset of chest pain. They were managed as anterior ST-segment elevation myocardial infarction without reperfusion treatment. Unfortunately, they experienced a recurrence of severe chest pain with cardiogenic shock during hospitalisation. The ECG recorded at that time showed a ST-segment re-elevation in infract-related leads.

RESULTS

The two cases were regrettably received a misjudgement of reinfarction at first, and one of the patients even was administrated with tirofiban. Afterwards the diagnosis of subacute LVFWR was made through antemortem echocardiography.

CONCLUSION

New ST-segment elevation (STE) in infarct-associated leads, coupled with recurrence of chest pain and new-onset hypotension, may constitute the premonitory signs of a subacute LVFWR.

Comparison of clinical outcomes between sufficient versus insufficient diagonal branch flow in anterior acute myocardial infarction

In primary percutaneous coronary intervention (PCI), revascularization to the main branch is considered to be more important than that to the side branch. The purpose of the present study was to compare in-hospital clinical outcomes between sufficient and insufficient diagonal flow in patients with anterior ST-elevation acute myocardial infarction. A total of 229 left anterior descending artery (LAD)-AMI with final Thrombolysis in Myocardial Infarction (TIMI)-3 LAD flow were included, and divided into the sufficient diagonal flow group (TIMI-3 diagonal flow: n = 170) and the insufficient diagonal flow group (TIMI ≤ 2 diagonal flow: n = 59). The primary endpoint was the incidence of mechanical complication. The secondary endpoints were incidences of in-hospital death, heart failure at discharge, and left ventricular thrombus. There were no significant differences in the primary endpoint (the sufficient diagonal flow group: 1.2%, the insufficient diagonal flow group: 0%, P = 0.403). In-hospital death was more frequently observed in the insufficient diagonal flow group (8.5%) than the sufficient diagonal flow group (2.9%) without reaching statistical significance (P = 0.073). The incidence of heart failure at discharge, and thrombus in left ventricular were not different between the two groups. In conclusion, in-hospital outcomes were not significantly different between the sufficient and insufficient diagonal flow groups. We may not stick to the diagonal flow in LAD-STEMI, as long as the LAD flow is maintained by PCI.

Acute left ventricular rupture following posterior wall myocardial infarction

Free wall rupture, the most fearful complication of myocardial infarction, mostly attacks anterior walls. Acute rupture is characterized by rapid development of mechanical arrest accompanied with bradyarrhythmia or electromechanical dissociation. The majority of patients succumb to death as the result of cardiac tamponade. Risk factors are advanced age, female gender, the first-time myocardial infarction, hypertension, and ST-segment elevation. We report a rare case of posterior wall myocardial infarction complicated with left ventricular rupture initially presenting with junctional escape rhythm.