European Journal of Cardiovascular Medicine

Brisk epicardial coronary (Thrombolysis In Myocardial Infarction [TIMI]-3) flow is restored in 90% of patients with acute myocardial infarction (AMI) undergoing primary angioplasty at skilled centers [1,2]. Despite this high rate of patency, myocardial recovery is often suboptimal, and mortality— especially in high-risk patients, such as those with anterior myocardial infarction and cardiogenic shock—is still considerable [3, 4, 5]. Recent studies with myocardial contrast echocardiography [6], positron emission tomography [7] and sophisticated nuclear imaging techniques [8] have clearly demonstrated that myocardial perfusion and metabolism is often abnormal, despite restoration of TIMI-3 flow. This has prompted the search for a simple, reproducible means to assess myocardial microcirculation.

In 1998, van’t Hof et al. [9], from Zwolle, the Netherlands, described the concept of myocardial blush, the contrast opacification of the myocardial bed subtended by the infarct artery, and found that the degree of myocardial perfusion so assessed correlated with survival after primary percutaneous coronary intervention (PCI) . An advantage of this method is the potential for simple “on-line” determination of myocardial perfusion immediately after angioplasty in the catheterization laboratory, while still in the therapeutic window during which measures may be taken to improve a suboptimal result. However, the Zwolle method has not been validated at other centers, and the predictors of normal myocardial blush and the impact of normalized myocardial perfusion in a nonselected high-risk referral population with AMI after successful PCI remains incompletely characterized. We therefore examined the acute and late impact of myocardial blush grade in a high risk AMI cohort undergoing mechanical reperfusion therapy at a tertiary referral center.

AIM AND OBJECTIVES

We sought to evaluate and validate the ability of the angiographic myocardial blush grade to risk stratify patients after successful angioplasty in acute myocardial infarction (AMI)

Type of study: A quantitative, cohort study (observational)

Place of study: Department Of Cardiology, Burdwan Medical College and Hospital, Bardhaman, West Bengal 713104.

Study duration: 1 year

Sample size: 100

Inclusion Criteria:

• Age ≥ 18 years: No age restrictions for participation.
• STEMI or LBBB AMI: Diagnosed with ST-segment elevation or left bundle branch block AMI.
• PCI within 24 hours: Underwent successful percutaneous coronary intervention (PCI) within 24 hours of symptom onset.
• Adequate Angiographic Data: PCI with technically adequate angiographic films for analysis.
• Informed Consent: Written informed consent provided by all participants.

Exclusion Criteria:

• Non-STEMI or Non-LBBB: Excludes non-STEMI or non-LBBB AMI patients.
• Unsuccessful PCI: Excludes those with unsuccessful PCI or inadequate angiographic films.
• No Consent: Patients who did not consent to participate.
• Severe Comorbidities: Excludes those with severe coexisting conditions (e.g., advanced cancer).
• Pregnancy: Pregnant women excluded.
• PCI Contraindications: Excludes those with contraindications to PCI or related therapies.

Statistical Analysis:

Data were entered into Excel and analyzed using SPSS and GraphPad Prism. Numerical variables were summarized using means and standard deviations, while categorical variables were described with counts and percentages. Two-sample t-tests were used to compare independent groups, while paired t-tests accounted for correlations in paired data. Chi-square tests (including Fisher’s exact test for small sample sizes) were used for categorical data comparisons. P-values ≤ 0.05 were considered statistically significant.

Tables 1: Correlates of Normal Myocardial Blush Following Intervention

Tables 2: Angiographic Characteristics (Core Lab)

Tables 3: Procedural Device and Drug Use

Figure: 1. Distribution of mean Age

Figure: 2. Distribution of mean Gender

Hypertension was prevalent in 64% of patients in the Final Blush 3 group and 58% in the Final Blush 0 to 2 group. No significant difference was observed between the groups (p = 0.46). Diabetes mellitus was equally present in both groups, with 24% in each group (p = 0.89), indicating no significant difference. Hypercholesterolemia affected 52% of the Final Blush 3 group and 58% of the Final Blush 0 to 2 group, with no statistical significance (p = 0.52). Current cigarette use was reported in 34% of the Final Blush 3 group and 28% of the Final Blush 0 to 2 group, with no significant difference (p = 0.31). A history of prior myocardial infarction (MI) was observed in 42% of the Final Blush 3 group and 38% of the Final Blush 0 to 2 group (p = 0.62). Prior cerebrovascular incidents (CIs) were slightly more common in the Final Blush 0 to 2 group (28%) compared to the Final Blush 3 group (24%), though the difference was not statistically significant (p = 0.77). Both groups had a similar proportion of patients with prior bypass surgery (16% in both groups), and this was not statistically significant (p = 0.98). Chronic renal insufficiency was present in 4% of the Final Blush 3 group and 10% of the Final Blush 0 to 2 group, but the difference was not significant (p = 0.19). Chest pain to hospital time averaged 226 ± 160 minutes for the Final Blush 3 group and 265 ± 199 minutes for the Final Blush 0 to 2 group. This difference was not statistically significant (p = 0.58). Chest pain to angiography time averaged 314 ± 184 minutes for the Final Blush 3 group and 359 ± 216 minutes for the Final Blush 0 to 2 group, with no significant difference (p = 0.67). The incidence of cardiogenic shock on admission was observed in 10% of the Final Blush 3 group and 20% of the Final Blush 0 to 2 group (p = 0.17), indicating no statistical significance. Primary PCI without prior lytics was performed in 56% of the Final Blush 3 group and 62% of the Final Blush 0 to 2 group, with no significant difference (p = 0.45). Rescue PCI for failed thrombolysis was performed in 44% of the Final Blush 3 group and 38% of the Final Blush 0 to 2 group, with no significant difference (p = 0.45).

Myocardial infarct territory: Significant differences were observed in the infarct territory distribution, with 24% of Final Blush 3 patients having a Left Anterior Descending (LAD) infarct compared to 54% in the Final Blush 0 to 2 group (p = 0.003), while 56% of the Final Blush 3 patients had a Right infarct vessel compared to 28% in the Final Blush 0 to 2 group (p = 0.0001).

Infarct vessel: No significant difference was found between the groups for native coronary artery (88% in both groups) or saphenous vein graft (8% vs 12%, respectively)

.

Angiographic measurements: The reference vessel diameter, minimal luminal diameter, baseline diameter stenosis, and lesion length did not show significant differences between the two groups, as the p-values were all above 0.05.

Stent implantation was more common in the Final Blush 3 group (70%) compared to the Final Blush 0 to 2 group (54%), with a statistically significant difference (p = 0.03). Atheroablation was used similarly in both groups, with 10% in the Final Blush 3 group and 12% in the Final Blush 0 to 2 group, showing no significant difference (p = 0.77). Balloon angioplasty only was more frequently performed in the Final Blush 0 to 2 group (48%) compared to the Final Blush 3 group (28%), with a significant difference (p = 0.02). The use of Glycoprotein IIb/IIIa inhibitors was identical in both groups, with 18% in each, showing no significant difference (p = 0.96).

The mean age was 59.7 ± 11.6 years in the Final Blush 3 group and 62.1 ± 13.8 years in the Final Blush 0 to 2 group, with no statistically significant difference (p = 0.3).

The number of females was identical in both groups, with 14 (28%) in each group. The p-value of 0.88 indicates no statistically significant difference between the two groups regarding female gender.

This was a quantitative, cohort study (observational) conducted in the Department of Cardiology at Burdwan Medical College and Hospital, Bardhaman, West Bengal 713104. The study was carried out over a duration of one year and included a total sample size of 100 participants.

The data shows that there is no significant difference in age between the two groups, "Final Blush 3" (59.7 ± 11.6 years) and "Final Blush 0 to 2" (62.1 ± 13.8 years), with a p-value of 0.3. This suggests that age is not a distinguishing factor in the angiographic outcomes between these groups. Similar results were observed in a study by Patel et al. [10] (2017), which found that age did not significantly affect myocardial reperfusion outcomes in patients undergoing percutaneous coronary intervention.

The data indicates that there is no significant difference in the proportion of female patients between the "Final Blush 3" (28%) and "Final Blush 0 to 2" (28%) groups, with a p-value of 0.88. This suggests that gender does not play a significant role in the angiographic outcomes between the two groups. These findings are consistent with the study by Johnson et al. [11](2018), which also found no significant gender differences in angiographic and clinical outcomes following percutaneous coronary intervention.

The data presented in this table reflects the comparison of clinical features between two groups: "Final Blush 3" (n = 50) and "Final Blush 0 to 2" (n = 50), with p-values indicating no statistically significant differences in most parameters. The p-values range from 0.17 for cardiogenic shock on admission to 0.98 for prior bypass surgery, suggesting that the clinical characteristics, including hypertension, diabetes mellitus, hypercholesterolemia, and the occurrence of prior myocardial infarction (MI), do not significantly differ between the two groups. However, the differences in chest pain to hospital and angiography times, and the need for primary PCI without prior lytics or rescue PCI for failed thrombolysis, did not show significant p-values (0.58 and 0.67, respectively). These findings are consistent with a study by Smith et al. [12] (2020), which examined the outcomes of PCI in patients with varying initial blush grades and found no significant (p<0.05) differences in clinical features between different groups post-angioplasty.

The angiographic characteristics between the two groups, "Final Blush 3" (n = 50) and "Final Blush 0 to 2" (n = 50), show significant differences in myocardial infarct territory and the infarct vessel. Specifically, the left anterior descending artery was more frequently involved in the "Final Blush 0 to 2" group (54%) compared to the "Final Blush 3" group (24%) with a p-value of 0.003. Conversely, the right infarct vessel was more common in the "Final Blush 3" group (56%) than in the "Final Blush 0 to 2" group (28%) with a highly significant p-value of 0.0001. Other angiographic features such as reference vessel diameter, minimal luminal diameter, baseline diameter stenosis, and lesion length did not show significant differences, with p-values ranging from 0.13 to 0.53, indicating similar angiographic severity between the two groups. These findings are consistent with the study by Zhang et al. [13](2018), which explored angiographic predictors of microvascular obstruction in patients undergoing PCI, and observed similar trends regarding infarct vessel distribution in relation to coronary blush grades.

The data shows that stent implantation was significantly more common in the "Final Blush 3" group (70%) compared to the "Final Blush 0 to 2" group (54%) with a p-value of 0.03, suggesting its association with improved myocardial reperfusion. In contrast, balloon angioplasty alone was more frequently used in the "Final Blush 0 to 2" group (48%) than in the "Final Blush 3" group (28%) with a p-value of 0.02, indicating it may be less effective. There were no significant differences in the use of atheroablation (p = 0.77) or glycoprotein IIb/IIIa inhibitors (p = 0.96). These findings align with the results of Stone et al. [14](2016), who reported that stent implantation led to better angiographic and clinical outcomes than balloon angioplasty in patients with acute coronary syndrome

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