The role of residual intrastent thrombus during primary angioplasty: insights from the COCTAIL II study

COVID-19 impact on ST-elevation myocardial infarction incidence rate in a Italian STEMI network: a U-shaped curve phenomenon

BACKGROUND

Public health emergencies such as the COVID-19 outbreak may impact on the incidence rate of ST-elevation myocardial infarction (STEMI) in severely affected areas. However, this phenomenon demands attention also in areas where media and patients were focused on the COVID-19 pandemic, but the healthcare system was not overwhelmed by the huge number of COVID-19 patients.

METHODS AND RESULTS

In this observational study, we compared the incidence rate of all consecutive STEMI patients admitted at the University Hospital of Trieste, Italy, during March and April 2020 with the same 2 months of the previous 5 years (2015-2019). Patient characteristics were compared between 2020 and 2019.The incidence rate of STEMI admission in March-April 2020 was lower than those in March-April 2015-2019, 36 vs. 56 cases per 100 000 inhabitants/year [relative risk (RR) 0.65, 95% confidence interval (95% CI) 0.42-0.96, P = 0.045]. Considering that the incidence rates were constant in the past years (P = 0.24), the turnaround in 2020 is most likely due to the COVID-19 outbreak. Interestingly, this reduction was a dynamic phenomenon with a U-shaped curve during the 2-month period. System-of-care times were similar between 2020 and 2019; however in 2020, patients presented more frequently signs of heart failure compared to 2019 (Killip class ≥2 in 68% vs. 29%, P = 0.003).

CONCLUSION

During the COVID-19 outbreak, we observed a marked reduction in the STEMI incidence rate. This U-shaped phenomenon demands attention because a potential cause for the decrease in STEMI incidence may include the avoidance of medical care. Public campaigns aiming to increase awareness of ischemic symptoms may be needed during community outbreak.

Correlates of Residual Thrombus Burden in Successfully Thrombolysed Patients of ST-Elevation Myocardial Infarction Receiving Dual Anti-Platelet Therapy

Background

Variable residual thrombus ranging from minimal to a large thrombus is seen in the culprit vessel after successful thrombolysis in ST-elevation myocardial infarction (STEMI). Factors associated with residual thrombus in thrombolysed patients are poorly understood. The objective of our study was to determine the correlates of residual thrombus burden in successfully thrombolysed STEMI patients receiving dual antiplatelet therapy.

Methods

In this prospective observational study of 60 successfully thrombolysed STEMI patients receiving dual antiplatelet therapy, various clinical and coronary angiographic features like residual thrombus burden, residual stenosis, and thrombolysis in myocardial infarction (TIMI) flow grade in the infarct-related artery were evaluated.

Results

Out of 60 patients, 49 and 11 patients, respectively, had low and high thrombus burden. Thirty-seven (75.5%) patients amongst low-grade thrombus had TIMI 3 flow, whereas seven (63.6%) amongst high thrombus burden had TIMI 2 flow indicating an association between residual thrombus burden and TIMI flow grade, which was statistically significant (p=0.009). Further, amongst the 39 patients who were 45 years old, a statistically significant association of age and residual stenosis (p = 0.039) was observed.

Conclusion

In successfully thrombolysed STEMI patients receiving dual antiplatelet therapy, there is an inverse correlation between residual thrombus burden and TIMI flow grade with high-grade residual thrombus associated with more frequent low TIMI flow. Further, significant residual stenosis is more common in patients older than 45 years of age, underscoring the necessity for invasive evaluation after successful thrombolysis.