Conservative management of patients with acute myocardial infarction and spontaneous acute patency of the infarct-related artery

Diffuse non-obstructive coronary artery disease: two clinical faces of the same disease-a case report

Background

Coronary artery disease has a long preclinical phase before manifesting itself clinically due to diffuse non-obstructive disease, stenoses, or thrombosis.

Case summary

We present a case of a middle-aged male complaining of atypical chest pain, then severe retrosternal pain, and, eventually, effort angina. We performed non-invasive testing, coronary angiography, intravascular imaging, and flow reserve tests, each as appropriate. Cardiovascular risk control, optimization of drug therapy, and percutaneous coronary intervention were considered trying to comply with the best clinical practice.

Discussion

Diffuse non-obstructive coronary artery disease may present clinically in different ways. Exercise stress test might be sufficient to assess effort angina before a potential angiography. Flow reserve tests across the diseased vessel can distinguish between diffuse and focal pattern of the disease and assist in the adequate selection of therapy. Finally, intravascular imaging is invaluable for the assessment of the plaque risk features.

Spontaneous Reperfusion in Patients with Transient ST-Elevation Myocardial Infarction-Prevalence, Importance and Approaches to Management

Patients with transient ST-elevation myocardial infarction (STEMI) or spontaneous resolution (SpR) of the ST-segment elevation on electrocardiogram could potentially represent a unique group of patients posing a therapeutic management dilemma. In this review, we discuss the potential mechanisms underlying SpR, its relation to clinical outcomes and the proposed management options for patients with transient STEMI with a focus on immediate versus early percutaneous coronary intervention. We performed a structured literature search of PubMed and Cochrane Library databases from inception to December 2020. Studies focused on SpR in patients with acute coronary syndrome were selected. Available data suggest that deferral of angiography and revascularization within 24-48 h in these patients is reasonable and associated with similar or perhaps better outcomes than immediate angiography. Further randomized trials are needed to elucidate the best pharmacological and invasive strategies for this cohort.

Plaque characteristics in patients with ST-segment elevation myocardial infarction and early spontaneous reperfusion

BACKGROUND

Early spontaneous reperfusion (ESR) is not an uncommon phenomenon in clinical settings.

AIMS

The aim of this study was to detect potential mechanisms of ESR in patients with STEMI.

METHODS

This prospective study enrolled a total of 241 consecutive patients with STEMI undergoing optical coherence tomography (OCT) from July 2016 to August 2019. Forty-five patients (18.7%) met angiographic ESR criteria (TIMI 3 flow on the initial angiogram). Among those without ESR (TIMI 0 flow on initial angiogram), 45 patients were assigned to the control group according to propensity score matching with the ESR group.

RESULTS

Although the baseline characteristics of the groups were comparable, non-ruptured plaque (62.2% vs 35.6%) predominated and plaque rupture (37.8% vs 64.4%) was less common in the ESR group (p=0.011). Red thrombus (44.4% vs 77.8%) was also less common in the ESR group (p=0.001). Lastly, compared to the control group, the ESR group underwent fewer emergent stent placements (68.9% vs 91.1%, p=0.008).

CONCLUSIONS

Relief of coronary occlusion induced by a non-ruptured plaque may contribute to ESR in patients with STEMI.

The association between T wave inversion in leads with ST-elevation and patency of the infarct-related artery

Background

Up to over half of the patients with ST-segment elevation myocardial infarction (STEMI) are reported to undergo spontaneous reperfusion without therapeutic interventions. Our objective was to evaluate the applicability of T wave inversion in electrocardiography (ECG) of patients with STEMI as an indicator of early spontaneous reperfusion.

Methods

In this prospective study, patients with STEMI admitted to a tertiary referral hospital were studied over a 3-year period. ECG was obtained at the time of admission and patients underwent a PPCI. The association between early T wave inversion and patency of the infarct-related artery was investigated in both anterior and non-anterior STEMI.

Results

Overall, 1025 patients were included in the study. Anterior STEMI was seen in 592 patients (57.7%) and non-anterior STEMI in 433 patients (42.2%). Among those with anterior STEMI, 62 patients (10.4%) had inverted T and 530 (89.6%) had positive T waves. In patients with anterior STEMI and inverted T waves, a significantly higher TIMI flow was detected (p value = 0.001); however, this relationship was not seen in non-anterior STEMI.

Conclusion

In on-admission ECG of patients with anterior STEMI, concomitant inverted T wave in leads with ST elevation could be a proper marker of spontaneous reperfusion of infarct related artery.

Outcomes of Patients Presenting With Clinical Indices of Spontaneous Reperfusion in ST-Elevation Acute Coronary Syndrome Undergoing Deferred Angiography

BACKGROUND

Few data are available regarding the optimal management of ST-elevation myocardial infarction patients with clinically defined spontaneous reperfusion (SR). We report on the characteristics and outcomes of patients with SR in the primary percutaneous coronary intervention era, and assess whether immediate reperfusion can be deferred.

METHODS AND RESULTS

Data were drawn from a prospective nationwide survey, ACSIS (Acute Coronary Syndrome Israeli Survey). Definition of SR was predefined as both (1) ≥70% reduction in ST-segment elevation on consecutive ECGs and (2) ≥70% resolution of pain. Of 2361 consecutive ST-elevation-acute coronary syndrome patients in Killip class 1, 405 (17%) were not treated with primary reperfusion therapy because of SR. Intervention in SR patients was performed a median of 26 hours after admission. These patients were compared with the 1956 ST-elevation myocardial infarction patients who underwent primary reperfusion with a median door-to-balloon of 66 minutes (interquartile range 38-106). Baseline characteristics were similar except for slightly higher incidence of renal dysfunction and prior angina pectoris in SR patients. Time from symptom onset to medical contact was significantly greater in SR patients. Patients with SR had significantly less in-hospital heart failure (4% versus 11%) and cardiogenic shock (0% versus 2%) (P<0.01 for all). No significant differences were found in in-hospital mortality (1% versus 2%), 30-day major cardiac events (4% versus 4%), and mortality at 30 days (1% versus 2%) and 1 year (4% versus 4%).

CONCLUSIONS

Patients with clinically defined SR have a favorable prognosis. Deferring immediate intervention seems to be safe in patients with clinical indices of spontaneous reperfusion.

Neutrophil to lymphocyte ratio in acute ST-segment elevation myocardial infarction

BACKGROUND

Spontaneous early patency of infarct-related artery (IRA) on arrival for primary percutaneous coronary intervention is associated with better short- and long-term prognosis in patients with ST-segment elevation myocardial infarction (STEMI). We aimed to investigate whether the hemographic parameters on admission are associated with spontaneous IRA patency.

METHODS

This was a retrospective study of 1,625 patients with acute STEMI who underwent primary percutaneous coronary intervention<12 hours after the onset of symptoms.

RESULTS

Angiography showed patent IRA (prethrombolysis in myocardial infarction [TIMI] grade 3 flow) in 160 (9.8%) patients. Neutrophil count on admission (7.8±2.4×10³/μL versus 9.7±3.8×10³/μL; P<0.001) was significantly lower and lymphocyte count (2.4±1.0×10³/μL versus 1.9±1.1×10³/μL; P<0.001) on admission was significantly higher in the patent IRA group. Neutrophil to lymphocyte ratio (NLR) was significantly lower in the patent IRA group (4.1±3.2 versus 6.9±5.5; P<0.001). Admission leukocyte counts (13±4.0×10³/μL versus 12±3.4×10³/μL; P<0.001) and NLR (7.2±5.8 versus 5.5±4.4; P<0.001) of the patients with TIMI thrombus score≥4 were significantly higher than patients with TIMI thrombus score<4. In the multivariate analysis, NLR≥4.5 (3.17 [95% confidence interval: 2.04-4.92]; P<0.001) was found to be independently predicting an occluded IRA on initial angiography with a sensitivity of 62.7% and a specificity of 70%.

CONCLUSIONS

NLR on admission is significantly related to angiographic thrombus burden and spontaneous early IRA patency in patients with acute STEMI.

Relation of clinically defined spontaneous reperfusion to outcome in ST-elevation myocardial infarction

In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI), a patent infarct-related artery on initial angiography was associated with better angiographic results and improved prognosis compared with patients without spontaneous reflow. Little is known about the prevalence, clinical course, and optimal management of patients presenting with clinical signs of spontaneous reperfusion (SR). The objective was to evaluate characteristics and clinical outcomes in patients with STEMI with clinical signs of SR. The study included 710 consecutive patients with STEMI eligible for reperfusion therapy who were followed up for 30 days. SR was defined as a >or=70% reduction in sum ST elevation and pain severity before initiation of reperfusion therapy. SR was observed in 155 patients (22%). Although almost all patients with STEMI without SR underwent primary reperfusion using primary PCI (398 of 555 patients; 72%) or thrombolysis (125 of 555; 23%), most patients with SR were initially treated conservatively, and primary PCI was performed in only 13 patients (8%). Although patients with SR had a higher incidence of recurrent in-hospital ischemia, they developed smaller myocardial infarctions and sustained less in-hospital cardiogenic shock, heart failure, and electrical complications and had lower 7- and 30-day mortality rates. On multivariate analysis, SR remained significantly associated with a lower incidence of the combined end point of 30-day mortality, congestive heart failure, and recurrent acute coronary syndrome. In conclusion, despite initial conservative therapy, the outcome of patients with SR was markedly better than for patients without SR who underwent primary reperfusion.

Spontaneous reperfusion in ST-elevation myocardial infarction: comparison of angiographic and electrocardiographic assessments

INTRODUCTION

Spontaneous reperfusion (SR) in ST-elevation myocardial infarction has traditionally been assessed by coronary angiography. The frequency of SR varies widely in prior studies, and the clinical implications in the modern reperfusion era are unclear. Accordingly, using data from the ASSENT 4 PCI (ASsessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention) study, we undertook a systematic assessment of SR using both electrocardiographic (ECG) and angiographic techniques.

METHODS AND RESULTS

Five hundred eighty-five patients randomized to the primary percutaneous coronary intervention (PCI) arm of ASSENT 4 PCI were studied: all had ECG and thrombolysis in myocardial infarction flow data available approximately 60 minutes after randomization and before PCI. Electrocardiographic SR (>/=70% ST-segment resolution) occurred in 14.9% (87/585) and angiographic SR (thrombolysis in myocardial infarction grade 3) in 14.7% (86/585) of patients. Thirty-day clinical outcomes of patients with ECG SR versus no ECG SR tended to have lower mortality (0% vs 3.4%, P = .091), a lower composite of death/shock/congestive heart failure (6.9% vs 12.2%, P = .148), and significant reductions in death/reinfarction (0% vs 5.6%, P = .014). By contrast, no such differences were evident in patients with angiographic SR versus no SR for death (2.3% vs 3.0%, P = 1.00), death/shock/congestive heart failure (9.3% vs 11.8%, P = .498), or death/reinfarction (2.3% vs 5.2%, P = .409).

CONCLUSIONS

Whereas the frequency of SR was comparable using either ECG or angiographic criteria, clinical outcomes were best aligned with ECG SR. These data support the role of the ECG in assessing reperfusion and likely reflect the overall impact of myocardial perfusion versus infarct-related artery epicardial patency alone.

Effect of clopidogrel plus aspirin on ST segments in patients with ST-elevation acute myocardial infarction

Spontaneous ST-segment resolution (STR) after acute ST-elevation myocardial infarction is associated with favorable outcomes. Effect on STR of newer, more powerful antiplatelet and antithrombotic agents is unclear. The aim of this study was to identify independent clinical and angiographic predictors of STR in patients with ST-elevation acute myocardial infarction before percutaneous coronary intervention. We studied 206 patients admitted with ST-elevation acute myocardial infarction, of whom 37 (18%) had STR. There were 12 deaths (5.8%) that occurred in the group without spontaneous STR. Patients with spontaneous STR were younger (55 vs 61 years old, p = 0.02), had shorter duration of symptoms (117 vs 212 minutes, p <0.0001), had preserved ejection fraction (55% vs 40%, p <0.0001), had shorter hospital stays, and had lower in-hospital arrhythmias or death. Independent predictors of STR, identified by stepwise logistic regression analysis, were early clopidogrel administration (odds ratio [OR] 2.10, 95% confidence interval [CI] 1.00 to 4.40, p = 0.045), single-vessel disease (OR 2.85, 95% CI 1.22 to 6.70, p = 0.02), chest pain duration (OR 0.98, 95% CI 0.98 to 0.99, p <0.0001), collaterals (OR 4.3, 95% CI 1.7 to 10.8, p = 0.002), circumflex as a culprit vessel (OR 4.74, 95% CI 1.5 to 14.95, p = 0.008), and coronary thrombus noted on angiography (OR 5.76, 95% CI 1.63 to 20.4, p = 0.006). In conclusion, early clopidogrel administration is associated with, and likely causal for, STR. Patients with thrombus, collateral flow, and circumflex culprit vessel are more likely to have STR. In addition, our study confirms previous findings that patients with STR have preserved left ventricular function and better hospital outcomes compared with those without STR.

Large intracoronary thrombi with good TIMI flow during acute myocardial infarction: four cases of successful aggressive medical management in patients without angiographically detectable coronary atherosclerosis

Four cases of young patients with acute myocardial infarction are discussed in which urgent angiography showed large intracoronary thrombus and TIMI (thrombolysis in myocardial infarction) flow > or = 2 in the infarct related artery. The rest of the coronary tree appeared to be free of detectable atherosclerosis. Percutaneous transluminal coronary angioplasty was not performed and an aggressive antiplatelet/anticoagulant treatment was administered (acetylsalicylic acid, clopidogrel, abciximab, and heparin). In all cases early angiographic control (1-12 days after AMI) showed disappearance of thrombus, no significant residual stenosis, and normal flow. No deterioration of left ventricular function was observed and the clinical course both in hospital and at five months' follow up was uneventful.

Improved prognosis of patients presenting with clinical markers of spontaneous reperfusion during acute myocardial infarction

OBJECTIVE

To describe the clinical features, management, and prognosis of patients presenting with clinical markers of spontaneous reperfusion (SR) during acute myocardial infarction (AMI).

DESIGN

Cohort study.

SETTING

National registry of 26 coronary care units.

PATIENTS

2382 consecutive patients with AMI.

MAIN OUTCOME MEASURES

Patient characteristics, management, and mortality.

RESULTS

The incidence of SR was 4% of patients (n = 98) compared with thrombolytic treatment (n = 1163, 49%), primary angioplasty (n = 102, 4%), and non-reperfusion (n = 1019, 43%). SR patients were more likely to develop less or no myocardial damage as indicated by a higher percentage of non-Q wave AMI (58% v 32%, 47%, and 44%, respectively, p < 0.0001), aborted AMI (25% v 9%, 8%, and 12%, p < 0.001), and lower peak creatine kinase (503 v 1384, 1519, and 751 IU, p < 0.0001). SR patients, however, were more likely to develop recurrent ischaemic events (35% v 17%, 12%, and 16%, respectively; p < 0.001) and subsequently were more likely to be referred to coronary angiography (67%), angioplasty (41%), or bypass surgery (16%, p < 0.001). Mortality at 30 days (1% v 8%, 7%, and 13%, respectively, p < 0.0001) and one year (6% v 11%, 12%, and 19%, p < 0.0001) was significantly lower for SR patients than for the other subgroups. By multivariate analysis, SR remained a strong determinant of 30 day survival (odds ratio (OR) 0.16, 95% confidence interval (CI) 0.01 to 0.74). At one year, the association between SR and survival decreased (OR 0.49, 95% CI 0.18 to 1.13).

CONCLUSIONS

Clinical markers of SR are associated with greater myocardial salvage and favourable prognosis. The vulnerability of SR patients to recurrent ischaemic events suggests that they need close surveillance and may benefit from early intervention.

Racial heterogeneity in coronary artery vasomotor reactivity: differences between Japanese and Caucasian patients

Japanese investigators have provided a substantial contribution in the understanding of coronary vasomotor reactivity. On occasions, their findings have been at variance with those undertaken on caucasian patients, raising speculation that vasomotor differences between races may exist. In a comparative review of the published literature, we evaluated the vasoreactive differences among Japanese and caucasian patients with variant angina or myocardial infarction. In variant angina, Japanese patients appear to have diffusely hyperreactive coronary arteries compared with caucasian people, manifested by their segmental rather than focal spasm, hyperreactive nonspastic vessels and multivessel spasm. These differences may reflect the increased basal tone among Japanese variant angina patients and may relate to controversial differences in endothelial nitric oxide production or autonomic nervous system activity. Provocative vasomotor studies of Japanese patients with a recent myocardial infarction report a higher incidence of inducible spasm than caucasian studies, an observation recently supported by a controlled study. Furthermore, the hyperreactivity was diffuse, occurring in both non-infarct- and infarct-related vessels. These observations support the existence of racial coronary vasomotor reactivity differences but require confirmation in further prospectively conducted studies.