A multicenter study on the clinical characteristics and risk factors of in-hospital mortality in patients with mechanical complications following acute myocardial infarction

Impact of High Care Unit Management on In-Hospital Mortality in Patients with ST-Elevation Myocardial Infarction

The impact of HCU management on the short-term prognosis of STEMI patients undergoing primary percutaneous coronary intervention (PCI) remains unclear.We retrospectively assessed 694 STEMI patients who underwent primary PCI at 8 regional general hospitals in Iwate Prefecture from 2014-2018. The patients were categorized based on the hospital to which they were admitted with or without HCUs (353 versus 341 patients, from 3 versus 5 hospitals, respectively). There was no significant between-group difference for overall in-hospital mortality (7% versus 10%, P = 0.174). However, in the Killip Class II or higher, in-hospital mortality was significantly lower among patients admitted to the HCU (20% versus 44%, P < 0.001). After propensity score matching, we found that overall in-hospital mortality was significantly lower in patients admitted to HCUs (2% versus 8%, P = 0.008). Furthermore, mortality rates for patients requiring mechanical ventilation or circulatory support were significantly lower for patients admitted to HCUs, with mortality rates of 30% versus 50% (P = 0.037).Our findings suggest that in hospitals without CCUs, systemic management through HCUs may significantly improve the survival prognosis of STEMI patients with Killip classification of II or higher.

Current Understanding of Timing of Surgical Repair for Ventricular Septal Rupture following Acute Myocardial Infarction

BACKGROUND

Ventricular septal rupture (VSR) is a mechanical issue that can occur following an acute myocardial infarction (AMI) and has a high mortality rate. It requires a comprehensive, team-based approach for prompt diagnosis and maintaining stable blood flow. While the occurrence of VSR has lessened over the past hundred years and advancements have been made in treatment techniques, the mortality rate within 30 days can still surpass 40 percent. Surgery is the primary treatment method. For patients with stable blood flow, it is generally considered safer to perform surgery 4-6 weeks after the AMI to repair the VSR. However, the timing of surgery for patients with early instability in their blood flow is still a topic of debate.

SUMMARY

There is a lack of set criteria and standards to determine the best time for surgery in patients with VSR following an infarction who have unstable blood flow, especially when considering the use of blood circulation support devices and other techniques for maintaining blood flow that are used in clinical settings.

KEY MESSAGES

This review outlines the features of different mechanical circulatory support devices utilized in treating VSR, along with the current scoring system designed to direct the treatment approach for VSR patients.

Time course of cardiac rupture after acute myocardial infarction and comparison of clinical features of different rupture types

Objective

This study aimed to investigate the time course of cardiac rupture (CR) after acute myocardial infarction (AMI) and the differences among different rupture types.

Method

We retrospectively analyzed 145 patients with CR after AMI at Shanxi Cardiovascular Hospital from June 2016 to September 2022. Firstly, according to the time from onset of chest pain to CR, the patients were divided into early CR (≤24 h) (n = 61 patients) and late CR (>24 h) (n = 75 patients) to explore the difference between early CR and late CR. Secondly, according to the type of CR, the patients were divided into free wall rupture (FWR) (n = 55) and ventricular septal rupture (VSR) (n = 90) to explore the difference between FWR and VSR.

Results

Multivariate logistic regression analysis showed that high white blood cell count (OR = 1.134, 95% CI: 1.019-1.260, P = 0.021), low creatinine (OR = 0.991, 95% CI: 0.982-0.999, P = 0.026) were independently associated with early CR. In addition, rapid heart rate (OR = 1.035, 95% CI: 1.009-1.061, P = 0.009), low systolic blood pressure (OR = 0.981, 95% CI: 0.962-1.000, P = 0.048), and anterior myocardial infarction (OR = 5.989, 95% CI: 1.978-18.136, P = 0.002) were independently associated with VSR.

Conclusion

In patients with CR, high white blood cell count and low creatinine were independently associated with early CR, rapid heart rate, low systolic blood pressure, and anterior myocardial infarction were independently associated with VSR.

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.

Association between acute myocardial infarction-to-cardiac rupture time and in-hospital mortality risk: a retrospective analysis of multicenter registry data from the Cardiovascular Research Consortium-8 Universities (CIRC-8U)

Despite the known association of cardiac rupture with acute myocardial infarction (AMI), it is still unclear whether the clinical characteristics are associated with the risk of in-hospital mortality in patients with AMI complicated by cardiac rupture. The purpose of this study was to investigate the association between the time of cardiac rupture occurrence and the risk of in-hospital mortality after AMI. We conducted a retrospective analysis of multicenter registry data from eight medical universities in Eastern Japan. From 10,278 consecutive patients with AMI, we included 183 patients who had cardiac rupture after AMI, and examined the incidence of in-hospital deaths during a median follow-up of 26 days. Patients were stratified into three groups according to the AMI-to-cardiac rupture time, namely the > 24-h group (n = 111), 24-48-h group (n = 20), and < 48-h group (n = 52). Cox proportional hazards regression analysis was used to estimate the hazard ratio (HR) and the confidence interval (CI) for in-hospital mortality. Around 87 (48%) patients experienced in-hospital death and 126 (67%) underwent a cardiac surgery. Multivariable Cox regression analysis revealed a non-linear association across the three groups for mortality (HR [CI]; < 24 h: 1.0, reference; 24-48 h: 0.73 [0.27-1.86]; > 48 h: 2.25 [1.22-4.15]) after adjustments for age, sex, Killip classification, percutaneous coronary intervention, blood pressure, creatinine, peak creatine kinase myocardial band fraction, left ventricular ejection fraction, and type of rupture. Cardiac surgery was independently associated with a reduction in the HR of mortality (HR [CI]: 0.27 [0.12-0.61]) and attenuated the association between the three AMI-to-cardiac rupture time categories and mortality (statistically non-significant) in the Cox model. These data suggest that the AMI-to-cardiac rupture time contributes significantly to the risk of in-hospital mortality; however, rapid diagnosis and prompt surgical interventions are crucial for improving outcomes in patients with cardiac rupture after AMI.

Mechanical Complications of Myocardial Infarction

In this retrospective observational study, we have examined the incidence, characteristics, and treatment of serious myocardial infarction (MI) -associated mechanical complications (MCs) occurring in Japanese patients in this era of percutaneous coronary intervention (PCI), focusing on frailty, nutrition, and clinical implication of surgery. Included were 883 patients who, having suffered an MI, had been admitted to Nihon University Hospital between January 2013 and April 2020. Fifteen (1.70%) of these patients had suffered a potentially catastrophic MC-ventricular free wall rupture (VFWR, n = 8), ventricular septal rupture (VSR, n = 6), or papillary muscle rupture (PMR, n = 1). Factors associated with the MCs were age, poor nutritional status, a high Killip class, delayed diagnosis of MI, a high lactate concentration, a low thrombolysis in myocardial infarction flow grade, and single-vessel disease. Thirty-day mortality among MC patients was 60% (9/15): 87.5% associated with VFWR, 33.3% associated with VSR and 0% associated with PMR. On adjusted multivariate analysis, occurrence of an MC was independently associated with 30-day mortality. Despite a high surgical risk (EuroSCORE II: 11.8 ± 4.7) with less frailty, 30-day mortality was lower among patients whose MC was treated surgically than among those whose MC was treated conservatively (40.0% versus 100.0%, respectively; P = 0.044).Our data suggest that surgical intervention can save patients with a life-threatening MI-associated MC and should be considered, if they are not particularly frail.

Recent insights into pathophysiology and management of mechanical complications of myocardial infarction

PURPOSE OF REVIEW

Mechanical complications of myocardial infarction are a group of postischemic events and include papillary muscle rupture resulting in ischemic mitral regurgitation, ventricular septal defect, left ventricle free wall rupture, pseudoaneurysm, and true aneurysm. Advances made in management strategies, such as the institution of 'Code STEMI' and percutaneous interventions, have lowered the incidence of these complications. However, their presentation is still associated with increased morbidity and mortality. Early diagnosis and appropriate management is crucial for facilitating better clinical outcomes.

RECENT FINDINGS

Although the exact timing of a curative intervention is not known, emerging percutaneous and transcatheter approaches and improving mechanical circulatory support (MCS) devices have greatly enhanced our ability to manage and treat some of the complications postinfarct.

SUMMARY

Although the incidence of mechanical complications of myocardial infarction has decreased over the past few decades, these complications are still associated with high rates of morbidity and mortality. The combination of early and accurate diagnosis and subsequent appropriate management are imperative for optimizing clinical outcomes. Although more randomized clinical trials are needed, mechanical circulatory support devices and emerging therapeutic strategies can be offered to carefully selected patients.

Surgical Treatment of Post-Infarction Left Ventricular Free-Wall Rupture: A Multicenter Study

BACKGROUND

Left ventricular free-wall rupture (LVFWR) is an uncommon but serious mechanical complication of acute myocardial infarction. Surgical repair, though challenging, is the only definitive treatment. Given the rarity of this condition, however, results after surgery are still not well established. The aim of this study was to review a multicenter experience with the surgical management of post-infarction LVFWR and analyze the associated early outcomes.

METHODS

Using the CAUTION (Mechanical Complications of Acute Myocardial Infarction: an International Multicenter Cohort Study) database, we identified 140 patients who were surgically treated for post-acute myocardial infarction LVFWR in 15 different centers from 2001 to 2018. The main outcome measured was operative mortality. Multivariate analysis was carried out by constructing a logistic regression model to identify predictors of postoperative mortality.

RESULTS

The mean age of patients was 69.4 years. The oozing type of LVFWR was observed in 79 patients (56.4%), and the blowout type in 61 (43.6%). Sutured repair was used in the 61.4% of cases. The operative mortality rate was 36.4%. Low cardiac output syndrome was the main cause of perioperative death. Myocardial rerupture after surgery occurred in 10 patients (7.1%). Multivariable analysis revealed that preoperative left ventricular ejection fraction (P < .001), cardiac arrest at presentation (P = .011), female sex (P = .044), and the need for preoperative extracorporeal life support (P = .003) were independent predictors for operative mortality.

CONCLUSIONS

Surgical repair of post-infarction LVFWR carries a high operative mortality. Female sex, preoperative left ventricular ejection fraction, cardiac arrest, and extracorporeal life support are predictors of early mortality.

Mortality and predictors of survival in patients with recent ventricular septal rupture

Ventricular septal rupture (VSR) is a rare but fatal complication after acute myocardial infarction (AMI). However, the mortality in patients with recent VSR and appropriate timing of surgical repair have not been clarified. To examine the background characteristics and mortality of VSR patients as well as the usefulness and appropriate timing of surgery in this patient cohort. Among 3,947 consecutive patients with AMI at our hospital, 39 patients diagnosed with VSR from 2002 to 2020 were included in the analysis. All patients underwent transthoracic echocardiography to confirm VSR on admission. Coronary angiography (CAG) and measurement of pulmonary-systemic flow ratio were performed before emergent surgery. The use of mechanical support devices before or after procedures was considered for all patients who underwent CAG. Basically, we performed emergent or urgent operations to patients who were in a shock state or who needed mechanical support. The final decision of the timing of the operation was made by the cardiac team. Patients' mean age was 76.3 years, and 33.3% of them were males. Most culprit lesions were located in the left anterior ascending artery (81.3%). The mean pulmonary-systemic flow ratio after VSR onset was 3.07 ± 1.98. On admission, 48.7% of patients were in a shock state. Surgical repair was possible in 28 patients at a median of 1 day after admission, with a mortality rate of 25%. Among all patients, the mortality rate was 43.6%. Survivors were significantly younger (71.3 ± 11.3 vs. 82.7 ± 6.2 years, p < 0.01), had higher mean arterial blood pressure (75.6 ± 14.4 vs. 62.8 ± 16.2 mmHg, p = 0.0496) and lower ejection fraction (44.3 ± 11.7% vs. 54.8 ± 7.9%, p = 0.04), and underwent surgical repair more frequently (95.5% vs. 41.2%, p < 0.01) than the non-survivors. In multivariate analysis, younger age (odds ratio [OR] 1.18 95% confidence interval [CI] 1.01-1.38, p = 0.04) and surgical repair (OR 0.04, 95% CI 0.00-0.73, p = 0.03) were significant predictors of survival. In surgical repair cases, time from admission to operation did not differ significantly between survivors and non-survivors. Surgical repair and younger age are predictors of survival in patients with recent VSR, but the timing of surgery was not.