Long-term outcomes following successful treatment of acute mesenteric ischemic event: A population-based observational study

Abstract

BACKGROUND

There is a lack of studies reporting long-term outcomes in patients surviving initial event of acute mesenteric ischemia (AMI).

AIM

To identify population-based outcomes and risk factors for mortality according to AMI subtypes.

METHODS

We performed overall survival analysis of all enrolled AMI patients and follow-up investigation on patients who survived beyond index admission. The demographics, diagnostic and management variables, in addition to causes of death, were accrued from the Estonian National Electronic Health Database and medical records between 2016 and 2024. Risk factors for mortality were analyzed using univariable and multivariable analyses for all AMI patients and separately for patients with superior mesenteric artery thrombosis. Survival curves were calculated using Kaplan–Meier estimators.

RESULTS

In total, 572 patients were analyzed for overall survival. There were 203 patients discharged alive after an AMI event, with a median age of 74 years (range 64–80 years) and a median follow-up time of 39 months (interquartile range 10–63 months). Overall 3-year and estimated 5-year survival was 19.2% and 15.6%, while 3-year and estimated 5-year survival of the discharged patients was 54.2% and 44.2%, respectively. Survival curves for all patients diverged between AMI subtypes, with improved survival in patients with superior mesenteric vein occlusion. The 3-year and estimated 5-year survival curves of discharged patients did not differ between the subtypes of AMI, however, the estimated 8-year survival curves showed improved survival in patients with nonocclusive mesenteric ischemia and superior mesenteric vein occlusion. The main cause of death after discharge (44.3%) was another cardiovascular event. Multivariable analysis including all discharged patients, revealed advanced age, disability, and high Charlson’s comorbidity index as significant risk factors and antithrombotic therapy as protective factors for mortality.

CONCLUSION

Risk factors for mortality for all patients were advanced age, disability, comorbidity, and lack of antithrombotic therapy. In superior mesenteric artery thrombosis, post-discharge antithrombotic therapy was associated with improved long-term survival, but this requires prospective validation, and optimal antithrombotic strategies still necessitate individualized evaluation.

Key Words: Acute mesenteric ischemia; Superior mesenteric artery; Long-term outcome; Population-based; Mortality risk factors

Core Tip: We observed overall improved survival for patients with superior mesenteric vein occlusion; however, for patients discharged alive, survival rates were higher in the case of nonocclusive mesenteric ischemia and superior mesenteric vein occlusion. The risk factors for mortality in all patients included age, disability, comorbidity, and lack of antithrombotic therapy. Our data suggest long-term survival benefit in patients with superior mesenteric artery thrombosis, who receive antithrombotic therapy following discharge. Future prospective studies should assess different regimens of antithrombotic therapy.

INTRODUCTION

Acute mesenteric ischemia (AMI) is a potentially curable vascular emergency if timely and appropriately managed. However, short-term mortality of AMI remains high, ranging from 49% to 64%[1,2]. The literature offers few studies on long-term outcomes and causes of death after successful management of AMI. No studies stratifying outcomes according to AMI subtype were available and our review only found studies in which the subtypes of AMI were pooled, or studies limited to one treatment method. Overall 3-year and 5-year survival (including in-hospital deaths) of surgically treated patients of all AMI subtypes has been found to be 23%–26% and 21%–23%, respectively[3,4], while 50% of the patients who were discharged from hospital were alive at 5 years, with deaths mainly related to cardiovascular comorbidity and malignant disease[5]. Among the AMI subtypes, surgically revascularized patients with arterial occlusive AMI showed an overall survival rate of 42% at 46 months (SD = 17.3); 33% and 17% at 5 years in various studies[6-8]. Three-year overall survival among patients with occlusion of superior mesenteric vein (SMV) was 36%, and among a patient group including surgically treated patients with arterial occlusion and nonocclusive mesenteric ischemia (NOMI) was 32%[9,10]. Overall survival at 3–5 years after AMI ranged from 20% to 30%; better survival is likely in specific subtypes of AMI, but this issue was insufficiently assessed in six studies[3,4,6,7,9,10]. Among patients discharged alive from the hospital, ~50% survived beyond 5 years; however, recent studies focusing on this cohort are not available[5].

Management after initial treatment of patients with thrombosis of superior mesenteric artery (SMA) is not well established. According to the European guidelines on chronic mesenteric ischemia, it is recommended to administer dual antiplatelet therapy for a minimum of 1 month, followed by lifelong antiplatelet monotherapy after endovascular management (stenting) of the mesenteric artery. For patients treated with direct oral anticoagulant, vitamin K antagonists or low-molecular weight heparin, as well as one antiplatelet agent for 4 weeks, is suggested[11]. The European Society of Vascular Surgery guidelines give only general recommendations (low level of evidence) for medical prevention with antiplatelet or anticoagulation treatment in patients wo have survived AMI[12]. The World Society of Emergency Surgery guidelines indicate moderate evidence supporting recommendation for anticoagulation in patients undergoing mesenteric revascularization, but no evidence for recommendation for antiplatelet use[13]. Recommendations for antithrombotic management after endovascular revascularization are vague, based mainly on data about chronic mesenteric ischemia. At the same time, there are no recommendations for patients with AMI who have been surgically revascularized or managed without revascularization. After vascular surgery for lower limb atherosclerosis, lifelong antiplatelet therapy is recommended[14], although there is a lack of evidence regarding whether the same intervention can improve outcomes following SMA occlusion.

Thus, the primary objective of this study was to provide new data on post-discharge long-term survival following AMI and to review the risk factors and causes of death among patients who survive after discharge. The secondary objectives were: To describe overall and post-discharge survival for AMI subtypes; establish the proportion of patients with SMA thrombosis undergoing long-term antiplatelet therapy; and identify mortality risk factors in patients with SMA thrombosis.

We hypothesized that for patients who have survived index admission, long-term survival rate varies among the different subtypes of AMI, and antithrombotic therapy after successful treatment of acute SMA thrombosis reduces mortality.

MATERIALS AND METHODS

Following approval from the Ethics Committee, we conducted a long-term follow-up investigation of patients from a previous population-based study of AMI in Estonia[1]. To identify the patients of interest, all billed cases by public healthcare providers were accrued from the Estonian National Electronic Health Database, which covers all Estonian hospitals, for patients aged ≥ 18 years with diagnostic and procedure codes for AMI between 2016 and 2020. International Classification of Diseases-10 diagnostic codes included I74.0, I74.1, I74.8, I74.9, I81, K55.0, K55.1, K55.8, K55.9, and NOMESCO procedure codes included PCE30, PCF30, PCG30, PCH30, PCJ30, PCK30, PCN30, PCP30, PCQ30, PCR30, and PCT30. The obtained cases were linked to the Estonian Causes of Death Registry for cause of death analysis. All selected cases’ medical charts were reviewed to confirm a true AMI diagnosis based on the following criteria. (1) Occlusive AMI: Appropriate clinical presentation of life-threatening acute intestinal ischemia with thrombosis or embolism of the mesenteric arteries or thrombosis of the mesenteric veins or ischemic intestinal findings, confirmed, on computed tomography scan, at surgery (laparoscopy/laparotomy), or at autopsy. (2) NOMI: Acute intestinal ischemia based on clinical presentation pattern and pathological intestinal findings on computed tomography scan, bowel necrosis on laparoscopy/laparotomy, or at autopsy without significant (> 70%) obstruction of the SMA or inferior mesenteric artery.

Follow-up lasted until January 2024, which allowed us to assess survival ranging from 3 to 8 years after discharge from hospital. We used a previously created database of the following subtypes of AMI: (1) SMA embolism; (2) SMA thrombosis; (3) SMA unclear occlusion; (4) SMV occlusion; (5) NOMI; (6) inferior mesenteric artery occlusion; and (7) unclear subtype of AMI.

Of the 577 patients enrolled, 572 were included in long-term follow-up analysis and calculation of overall survival, after excluding five who were lost to follow-up. The patients discharged from hospital alive (n = 203) were involved in the analysis of survival following discharge. The collected variables included AMI subtype, treatment method of AMI, age, sex, and disability (need for assistance in daily life). The additional variables included in the follow-up period were comorbidities that were required to calculate age-adjusted Charlson’s comorbidity index (ACCI)[15], disability after the AMI event (assistance with daily life, including those with disability before AMI and those with newly developed disability), recurrence of AMI, other cardiovascular events, anticoagulation or antiplatelet therapy, smoking, time of death, and cause of death.

All causes of death were collected and divided into four subgroups: Recurrent AMI event; other cardiovascular events (cerebrovascular accident or transient ischemic attack, myocardial infarction, or peripheral vascular disease); miscellaneous causes; and unknown cause. The data about variables was retrieved from the Estonian National Electronic Health Database.

Statistical analysis

The data was presented as n (%), or medians with interquartile range. For comparisons between two groups, Fisher’s exact test or the Mann–Whitney U test was used. When comparing median ages of patients, the Kruskal–Wallis test was deployed. Statistical significance was defined as P < 0.05. Complete-case analysis was used in case of missing data. Age, sex, disability, diabetes, smoking status, ACCI, anticoagulation and/or antiplatelet therapy (all antithrombotic regimes combined), bowel resection at index hospitalization, and AMI subtype were considered as factors potentially influencing mortality for all subtypes of AMI. Age, sex, disability, smoking status, hypertension, atherosclerosis, ACCI, antithrombotic therapy, revascularization, and bowel resection at index hospitalization were considered as factors potentially influencing mortality for patients with thrombosis of SMA. Cox proportional hazards models were used for analysis of mortality risk factors. Potential risk factors were tested in univariable analysis and variables with P < 0.1 were included in multivariable analysis. Antiplatelet therapy as a potential risk factor for mortality was tested in a similar model with the same covariates as antithrombotic therapy. Additional analysis was performed on antiplatelet therapy and its relation to atherosclerotic complications (recurrent AMI, cerebrovascular accident, myocardial infarction, and limb ischemia caused by atherosclerosis) in SMA thrombosis. AMI subtypes were compared with SMA occlusion (SMA embolism, SMA thrombosis, and SMA unclear occlusion combined). Survival analyses were made separately for overall survival (including in-hospital deaths) and for survival after discharge for all AMI patients and for all AMI subtypes. Overall survival was calculated as time in months after the AMI event, and survival after discharge as time in months after discharge.

The survival curves were visualized using Kaplan–Meier estimators and compared with G-rho family of tests. In the Kaplan–Meier curves, the patients who were alive or lost to follow-up at their last known time point were considered censored, meaning their survival time lasted up to that point only. Analysis was conducted in R[16] and the survival package[17] was used for survival analysis. Statistical analyses were carried out by a biomedical statistician.

RESULTS

Out of a total of 577 patients with AMI, 208 were discharged, and five were lost to follow-up. Thus, 572 patients were included in the analysis of overall survival and 203 patients were included in long-term follow-up analysis (Figure 1).

Figure 1  Study flowchart.

Demographics and management of survivors at initial hospitalization

Among the 203 patients included in the follow-up analysis, the main subtype of AMI was SMA thrombosis (60 patients, 30%). Median age for the different subtypes of AMI were comparable, except for occlusion of SMV, for which median age was considerably lower compared to the other subtypes (63 years, P = 0.025) (Table 1). Median age and interventions used at index-hospitalization are presented in Table 1.

Table 1 Management at initial hospitalization.

Management	All	Occlusive					Nonocclusive mesenteric ischemia	Unclear
		Embolism1	Thrombosis1	Unclear1	Inferior mesenteric artery	Superior mesenteric vein
Number of patients	203	11	60	36	30	17	12	37
Median age at index hospitalization in years (interquartile range)	74 (64-80)	74 (70-84)	78.5 (70-84)	72.5 (62-82)	77 (65-81)	63 (51-71)	79.5 (69-81)	72 (64-80)
Revascularization	45	7	25	8			1	4
Revascularization and bowel resection	19	1	15	3
Bowel resection	71	3	14	13	12	6	6	17
Conservative treatment	68		6	12	18	11	5	16

¹Superior mesenteric artery.

Survival after AMI event

Overall (n = 572, including in-hospital deaths) 3-year (110/572) and 5-year estimated survival was 19.2% [95% confidence interval (CI): 16.3%–22.7%)] and 15.6% (95%CI: 12.9%–19.0%), respectively (Figure 2A). The median follow-up time after discharge was 39 months (interquartile range 10–63 months). Following discharge, 3-year (110/203) and 5-year estimated survival was at 54.2% (95%CI: 47.7%–61.5%) and 44.2% (95%CI: 37.6%–51.9%), respectively (Figure 2B). In total, 122 (60%) patients died during the follow-up period ranging from 3 to 8 years. Other cardiovascular event was documented as the main cause of death (44.3%) for all AMI patients. The predominating miscellaneous causes included pneumonia, followed by urinary tract infection, and cancer-related causes (Table 2).

Figure 2 Kaplan–Meier overall and post-discharge survival for subtypes of consolidated acute mesenteric ischemia. A: Kaplan–Meier overall; B: Post-discharge survival. AMI: Acute mesenteric ischemia.

Table 2 The 3- and estimated 5-year overall and post-discharge survival and causes of death for subtypes of acute mesenteric ischemia, n (%).

AMI subtype	Overall (including in-hospital deaths) survival (%), 95%CI		Post-discharge survival (%), 95%CI		Causes of death
	3-year	Estimated 5-year	3-year	Estimated 5-year	New AMI event	Other cardiovascular event	Miscellaneous causes of death	Unknown cause of death
SMA embolism	12.8 (5.7-29.1)	12.8 (5.7-29.1)	45.5 (23.8-86.8)	45.5 (23.8-86.8)	-	6 (100.0)	-	-
SMA thrombosis	15.0 (10.6-21.1)	10.8 (7.1-16.4)	46.7 (35.6-61.2)	33.5 (23.2-48.4)	9 (20.0)	17 (37.8)	15 (33.3)	4 (8.9)
SMA unclear occlusion	14.3 (9.2-22.2)	10.7 (6.2-18.5)	47.2 (33.4-66.7)	35.7 (22.3-57.1)	4 (16.0)	10 (40.0)	6 (24.0)	5 (20.0)
Inferior mesenteric artery occlusion	40.0 (27.4-58.5)	30.3 (18.3-50.1)	53.3 (38.2-74.5)	41.3 (26.3-64.7)	-	10 (58.8)	6 (35.3)	1 (5.9)
Superior mesenteric vein occlusion	52.0 (35.7-75.8)	35.5 (28.8-72.0)	76.5 (58.7-99.5)	68.0 (47.9-96.5)	-	1 (20.0)	3 (60.0)	1 (20.0)
Non-occlusive mesenteric ischemia	19.0 (10.2-35.5)	19.0 (10.2-35.5)	66.7 (44.7-99.5)	66.7 (44.7-99.5)	-	2 (50.0)	2 (50.0)	-
Unclear	19.2 (13.3-27.7)	16.3 (10.8-24.6)	62.2 (48.3-79.9)	53.1 (39.0-72.3)	1 (5.0)	8 (40.0)	7 (35.0)	4 (20.0)
P value	P < 0.001	P < 0.001	P = 0.3	P = 0.1	P = 0.278

AMI: Acute mesenteric ischemia; CI: Confidence interval; SMA: Superior mesenteric artery.

Survival after AMI according to the subtypes

The Kaplan–Meier estimator was used for the survival curves for all subtypes of AMI (Figure 3A). There was a significant difference in overall (including in-hospital deaths) survival between AMI subtypes (Table 2), with SMV occlusion resulting in best survival (P < 0.01). In post-discharge survival analysis (Figure 3B), there was no difference in 3-year or estimated 5-year survival between the AMI subtypes. However, estimated 8-year survival analysis revealed a significant difference in favor of SMV occlusion and NOMI (P = 0.01), although the actual number of patients under observation beyond 6 years of follow-up was low.

Figure 3 Kaplan–Meier overall and post-discharge survival for subtypes of acute mesenteric ischemia. A: Kaplan–Meier overall; B: Post-discharge survival. AMI: Acute mesenteric ischemia; IMA: Inferior mesenteric artery; NOMI: Nonocclusive mesenteric ischemia; SMA: Superior mesenteric artery; SMV: Superior mesenteric vein.

Analysis of risk factors for mortality in all AMI patients

Multivariable analysis identified advanced age, disability, and higher ACCI as the independent risk factors for mortality among all discharged AMI patients. In contrast, NOMI and use of antithrombotic therapy demonstrated a protective effect (Table 3).

Table 3 Univariable and multivariable analysis evaluating the risk factors for mortality for all patients with acute mesenteric ischemia.

Variable	Hazard ratio (95%CI)	P value
Univariable analysis
Sex (female)	0.99 (0.68-1.41)	0.936
Age	1.05 (1.03-1.07)	< 0.001
Disability (yes)	2.95 (2.05-4.24)	< 0.001
Diabetes (yes)	0.95 (0.55-1.64)	0.867
Smoking
Yes	0.57 (0.31-1.06)	0.074
Quit after AMI	0.39 (0.09-1.58)	0.186
Antithrombotic (yes)	0.63 (0.42-0.93)	0.020
Bowel resection (yes)	1.30 (0.68-2.48)	0.422
Age-adjusted Charlson index	1.25 (1.16-1.34)	< 0.001
AMI type
Unclear	0.62 (0.37-1.02)	0.057
IMA occlusion	0.73 (0.43-1.25)	0.248
NOMI	0.31 (0.11-0.85)	0.022
SMV occlusion	0.33 (0.13-0.82)	0.016
Multivariable analysis
Age	1.04 (1.01-1.06)	< 0.001a
Disability (yes)	1.86 (1.22-2.81)	0.003a
Smoking
Yes	0.70 (0.37-1.33)	0.275
Quit after AMI	0.49 (0.11-2.17)	0.347
Antithrombotic (yes)	0.40 (0.25-0.63)	< 0.001a
Age-adjusted Charlson index	1.17 (1.06-1.28)	0.001a
AMI type
Unclear	0.78 (0.46-1.32)	0.354
IMA occlusion	0.60 (0.34-1.05)	0.073
NOMI	0.19 (0.06-0.56)	0.002a
SMV occlusion	1.01 (0.39-2.61)	0.983

^aP < 0.05.

AMI: Acute mesenteric ischemia; CI: Confidence interval; IMA: Inferior mesenteric artery; NOMI: Non-occlusive mesenteric ischemia; SMV: Superior mesenteric vein.

Analysis of risk factors for mortality in patients with SMA thrombosis

Multivariable analysis revealed disability as an independent risk factor for mortality in discharged patients with SMA thrombosis, and antithrombotic therapy as an independent protective factor (Table 4).

Table 4 Univariable and multivariable analysis evaluating the risk factors for mortality for patients with superior mesenteric artery thrombosis.

Variable	Hazard ratio (95%CI)	P value
Univariable analysis
Age	1.04 (1.00-1.07)	0.011
Sex (female)	0.83 (0.45-1.49)	0.527
Disability (yes)	2.74 (1.48-5.08)	0.001
Smoking (yes)	0.71 (0.21-2.31)	0.569
Hypertension (yes)	1.78 (0.62-4.99)	0.279
Atherosclerosis (yes)	0.68 (0.89-4.38)	0.090
Age-adjusted Charlson index	1.16 (1.02-1.31)	0.019
Antithrombotic (yes)	0.29 (0.12-0.64)	0.002
Revascularization (yes)	0.84 (0.45-1.54)	0.565
Bowel resection (yes)	5.06 (1.18-21.53)	0.028
Multivariable analysis
Age	1.02 (0.96-1.08)	0.429
Disability (yes)	6.62 (2.19-20.06)	< 0.001a
Atherosclerosis (yes)	2.18 (0.51-9.22)	0.288
Antithrombotic (yes)	0.07 (0.01-0.38)	0.002a
Bowel resection (yes)	1.83 (0.32-10.26)	0.490
Age-adjusted Charlson index	0.90 (0.70-1.16)	0.410

^aP < 0.05. CI: Confidence interval.

A total of 60 patients with thrombosis of SMA were discharged, and 20 (33%) were administered long-term antiplatelet therapy. Dual antiplatelet therapy for 4 months was administered to one patient, and all others received monotherapy with acetylsalicylic acid at a dose of 75 mg/day. Overall, 45 (75%) patients died in follow-up period. In almost half (n = 21) of the cases, death was caused by an atherosclerotic complication (recurrent AMI, cerebrovascular accident, myocardial infarction, and limb ischemia caused by atherosclerosis). Analysis showed that the patients to whom antiplatelet medication was not administered (n = 40, 67%) had significantly more atherosclerotic complications (50% vs 3%, P = 0.027) and increased mortality compared to the patients who received antiplatelet drugs (45% vs 15%, P = 0.026). However, antiplatelet therapy was not an independent risk factor of all-cause mortality in patients with SMA thrombosis (P = 0.695) in multivariable analysis.

DISCUSSION

In this retrospective population-based study, we describe long-term survival and outline the factors potentially influencing it for patients who were discharged alive from the hospital after the initial event of AMI.

We identified an overall survival at 3 years after discharge following AMI event at 19%, which is comparable to the results of Acosta-Mérida et al[3] and Marchena-Gomez et al[4] who reported an overall 3-year survival of 26% and 23%, respectively. However, as previously stated, both of these studies were performed only on surgically treated patients. When all in-hospital deaths were included, our cohort experienced a significant difference in survival between the subtypes of AMI, suggesting survival benefit to the subgroup of patients with SMV occlusion. These survival rates are higher, compared to those presented in a previous study on mesenteric venous thrombosis[10]; possibly owing to the improvements in provision and monitoring of anticoagulants over time.

The follow-up results of AMI patients discharged alive, with up to 8-year survival estimates, confirm that hospital survivors may have an adequate long-term prognosis after successful management of AMI. The survival curves with different courses for the different subtypes of AMI suggest improved survival for patients with NOMI and SMV occlusion. Yet, there was no significant difference in 3-year or estimated 5-year survival between the AMI subtypes after discharge. Nevertheless, the survival curves diverged when the maximum follow-up period of 8 years was considered, suggesting better estimated survival for patients with NOMI and SMV occlusion. However, this was limited to only a few patients who were still under observation close to the end of the maximum follow-up period. The above results are hypothesis-generating and indicate, on the one hand, the importance of differences in pathophysiology between the different subtypes of AMI, but, on the other hand, a potential for improvement in the long-term management of survivors with arterial occlusive AMI.

The potential reasons for SMV occlusion include inherited or acquired thrombophilia, inflammation, and venous stasis, most commonly portal hypertension, with the main management targets being the underlying cause and administration of anticoagulants[12,18]. Thus, in the case of this subtype of AMI, when the underlying cause is adequately treated and a sufficient dose of anticoagulants is timely administered, the acute event may be survived without continuing mortality risks. In our study, patients with SMV occlusion were considerably younger compared to the other AMI subtypes. NOMI was associated with better survival, compared to other subtypes, for the patients discharged from the hospital alive. NOMI and SMV occlusion share a similarity, as the underlying disease is not necessarily atherosclerosis and chronic cardiovascular pathology. As in SMV occlusion, if the underlying cause of NOMI is treated and the patient survives, continuing mortality risk may be lower than in arterial occlusive AMI associated with high risk of cardiovascular complications.

According to the multivariable analysis of all discharged AMI patients, increasing age, disability, and more comorbidities were associated with increased mortality during our follow-up, while antithrombotic therapy and NOMI as a subtype appeared to be protective. A meta-analysis based on six studies suggested survival benefit from anticoagulation to patients with AMI[19]. We found that the main cause of death in all AMI patients was other cardiovascular events, which is in line with the findings by Klempnauer et al[5]. Similarly, cardiovascular events are the most frequent cause of death among the general population in Europe[20]. Based on the literature, the suggested treatment with antiplatelet drugs for arterial thrombosis, and anticoagulants for embolism and vein thrombosis has some overlapping effects[21]. Therefore, as a risk factor for all AMI subtypes, all antithrombotic regimens were analyzed together. A similar approach has been used for general statements in guidelines[12,13], but it is clearly less appropriate for assessing the specific subtypes of AMI. As our sample size did not allow assessment of all subtypes separately, only the largest subgroup of patients with SMA thrombosis was analyzed separately.

We observed 3-year and estimated 5-year survival rates of 47% and 34%, respectively, for patients with SMA thrombosis. In the case of SMA thrombosis, it could be possible to directly address the underlying cause, most commonly atherosclerosis[22-24], which may lead to improved survival with reduction in atherosclerosis-related deaths. Accordingly, we hypothesized that after successful treatment of acute SMA thrombosis, antiplatelet therapy may reduce atherosclerosis-related mortality, which proved to be correct. We evaluated the effect of antiplatelet therapy as the primary option for atherosclerosis after SMA thrombosis, and noted that the patients who did not receive antiplatelet medication had higher risk for further atherosclerosis-related complications and death, compared to those who received antiplatelet agents.

To the best of our knowledge, the current investigation is a pioneering population-based study reporting long-term survival for all subtypes of AMI, focusing separately on hospital survivors and assessing the risk factors for long-term survival in AMI in general and in SMA thrombotic occlusion in particular. Still, the study had limitations due to its retrospective design, which makes the precise diagnosis of AMI subtypes in all instances and the assessment of the burden of disability difficult. The sample sizes were small and should be interpreted cautiously; consequently, different treatment modalities could not be analyzed separately. Different regimens of antithrombotic treatment were not assessed. Furthermore, the study cohort was formed of a limited number of patients who had different follow-up periods, and the causes of death were grouped for analysis.

CONCLUSION

We observed overall improved survival for patients with SMV occlusion; however, for patients who were discharged alive, survival rates were higher in those with NOMI or SMV occlusion. The risk factors for mortality for all patients included advanced age, disability, comorbidity, and lack of antithrombotic therapy. In SMA thrombosis, post-discharge antithrombotic therapy was associated with improved long-term survival, but this finding requires prospective validation, and optimal antithrombotic strategies still necessitate individualized evaluation.