Predicting ischemic mitral regurgitation in patients with acute ST-elevation myocardial infarction: Does time to reperfusion really matter and what is the role of collateral circulation?

Relationship between stress hyperglycemia and worsening heart failure in patients with significant secondary mitral regurgitation

BACKGROUND AND AIMS

Secondary mitral regurgitation (sMR), a major valvular disease, is prevalent in patients with coronary artery disease (CAD), and is associated with higher incidence of heart failure (HF) and mortality when present in combination with abnormal glucose metabolism. We aimed to evaluate the relationship between stress hyperglycemia ratio (SHR) and worsening HF in CAD patients with significant (grade ≥2) sMR.

METHODS

We performed a multi-center observational study of 874 participants with significant sMR following percutaneous coronary intervention (PCI) in the Cardiorenal Improvement-II (CIN-II) cohort. Patients with glucose and glycated hemoglobin (HbA1c) data at admission were included in the analysis, and categorized according to the SHR, the ratio of mmol/L blood glucose to % HbA1c, as quartiles: Q1: <0.74; Q2: 0.74-0.91; Q3: 0.91-1.14; and Q4: ≥1.14. The primary clinical endpoint was worsening HF and the secondary endpoint was major adverse cardiac events (MACE).

RESULTS

Of the 874 participants (64.1 ± 10.8 years, 80% male), 174 showed worsening HF and 226 developed MACE during a median follow-up of 3.7 years (interquartile range: 1.8-6.2 years). Compared to participants in the lowest quartile (Q1) of SHR, the highest quartile group (Q4) was at significantly higher risks of worsening HF (adjusted hazard ratio, 2.44; 95% confidence interval, 1.51-3.94; p< 0.001), while this was not associated with increased risk of MACE (p>0.05) after adjustment for potential covariates. For worsening HF, the results obtained for the normal glucose regulation subgroup may be more meaningful than those for the diabetes mellitus (DM) and pre-DM groups (p-interaction<0.001). For MACE, the acute myocardial infarction (AMI) (Q4 vs. Q1; HR: 0.65, 95%CI: 0.26-1.59) and non-AMI (Q4 vs. Q1; HR: 2.20, 95%CI: 1.36-3.54) subgroups differed significantly on MACE (p-interaction = 0.006).

CONCLUSIONS

Increasing SHR is associated with a higher risk of worsening of HF in patients with significant sMR, especially in those with normoglycemia.

Non-revascularized chronic total occlusions impact on substrate and post-ablation results in drug-refractory electrical storm

Background and aims

There is limited data concerning the effect of non-revascularized chronic total occlusions (NR-CTOs) after VT ablation. This study sought to evaluate the impact of NR-CTOs after ablation for electrical storm (ES).

Methods

Post-hoc retrospective analysis of data regarding 64 consecutive post-myocardial infarction patients (out of which 12 patients with NR-CTOs and 52 without NR-CTOs) undergoing substrate ablation for ES with an available median follow-up of 37.53 (7.25-64.65) months. Ablation result was assessed by inducibility of sustained monomorphic VT (SMVT) during final programmed ventricular stimulation (PVS). The primary endpoints were all-cause mortality and VT/VF recurrences after ablation, respectively, stratified by the presence of NR-CTOs. The secondary endpoint was to assess the predictive effect of NR-CTOs on all-cause mortality and VT/VF recurrences in relation to other relevant prognostic factors.

Results

At baseline, the presence of NR-CTOs was associated with higher bipolar BZ-to-total scar ratio (72.4% ± 17.9% vs. 52% ± 37.7%, p = 0.022) and more failure to eliminate the clinical VT (25% (3) vs. 0% (0), p < 0.001). During follow-up, overall all-cause mortality and recurrences were more frequent in the NR-CTO subgroup (75% (9) vs. 19.2% (10), log rank p = 0.003 and 58.3% vs. 23.1% (12), log rank p = 0.042 respectively). After adjusting for end-procedural residual SMVT inducibility, NR-CTOs predicted death during follow-up (HR 3.380, p = 0.009) however not recurrence (HR 1.986, p = 0.154).

Conclusions

NR-CTO patients treated by RFCA for drug-refractory ES demonstrated a higher ratio of BZ-to-total-scar area. In this analysis, NR-CTO was associated with worse acute procedural results and may as well impact long-term outcomes which should be further assessed in larger patient populations.

Association between triglyceride glucose index and worsening heart failure in significant secondary mitral regurgitation following percutaneous coronary intervention

BACKGROUND

The triglyceride glucose (TyG) index is an alternative to insulin resistance (IR) as an early indicator of worsening heart failure (HF). Patients with secondary mitral regurgitation (sMR) often experience progressive deterioration of cardiac function. This study aimed to investigate the relationship between the TyG index and worsening of HF in significant sMR (grade  ≥ 2) following percutaneous coronary intervention (PCI).

METHODS

This study enrolled participants with significant sMR following PCI from a multicenter cohort study. The patients were divided into the following 3 groups according to tertiles of TyG index: T1, TyG ≤ 8.51; T2, TyG > 8.51 to ≤ 8.98; and T3, TyG > 8.98. The main clinical outcome was worsening HF including unplanned rehospitalization or unscheduled physician office/emergency department visit due to HF and unplanned mitral valve surgery.

RESULTS

A total of 922 patients (mean ± SD age, 64.1 ± 11.0 years; 79.6% male) were enrolled. The incidence of worsening HF was 15.5% in T1, 15.7% in T2, and 26.4% in T3. In the multivariable model, the highest TyG tertile (T3 group) was more strongly correlated with worsening HF than the lowest tertile (T1 group) after adjusting for confounders (adjusted hazard ratio, 2.44; 95% confidence interval, 1.59-3.72; P < 0.001). The addition of TyG to risk factors such as N-terminal pro brain natriuretic peptide and clinical models improved the predictive ability of TyG for worsening HF.

CONCLUSIONS

Elevated preprocedural TyG index is a significant and independent risk factor for worsening HF in sMR following PCI that can be used for risk stratification.

In-Hospital Mortality in Patients With Acute ST-Elevation Myocardial Infarction With or Without Mitral Regurgitation

Background Mitral regurgitation (MR) is a common complication in hospitalized cardiac patients with ST-segment elevation myocardial infarction (STEMI); however, the patient outcomes depend on various factors that vary across facilities and regions. There is an acute need to stratify STEMI patients by risk of in-hospital mortality. We conducted this study to compare the mortality of patients with acute STEMI with or without MR admitted to different units of the Cardiology Department at Lady Reading Hospital (LRH) in Peshawar. Methods In this prospective study, we compared the mortality rates of STEMI patients with and without MR from June 5 to October 30, 2021. All patients with different types of STEMI treated at LRH were enrolled in the study regardless of age and gender. ST-elevation was confirmed via electrocardiogram, and MR was confirmed via echocardiography. We excluded any patients with primary organic valve disease or congenital heart disease. We also collected patient demographic and clinical characteristics. We used IBM SPSS Statistics for Windows, Version 24.0 (IBM Corp., Armonk, NY) for statistical analyses. Results Our study population included 228 patients with a mean age of 62.4 ± 12.3 years. Most of the patients were men (n=140; 61.4%), and only 78 (38.6%) were women. The prevalence of MR was 29.4%. Hypertension was the most common comorbidity (63.6%), and inferior wall myocardial infarction (MI) was the most common type of MI (49.1%). Hypertension, prehospital cardiopulmonary resuscitation (CPR), and Killip class ≥ 2 were significantly associated with MR (p<.001). In-hospital mortality was 29.8%, significantly associated with MR (p=.0001). Patients who needed CPR prior to hospitalization and those with Killip class ≥ 2 were less likely to survive (p=.0001). Conclusions MR is common following MI, especially in cases of inferior wall MI. Patients with MR have a poorer prognosis than those without MR following MI, more so when combined with other comorbidities. Regarding its relation to MI complications, an assessment of the MR is necessary to make an appropriate decision for treatment.

Complicating Acute Myocardial Infarction. Current Status and Unresolved Targets for Subsequent Research

Mechanical reperfusion with primary angioplasty, as the treatment of choice in acute myocardial infarction (MI), is associated not only with a high percentage of full epicardial and tissue reperfusion but also with a very good immediate and long-term clinical outcome. However, the Achilles heel of MI treatment is its ensemble of complications, such as cardiogenic shock due to severe systolic and/or diastolic dysfunction or MI mechanical complications, including perforation of the left ventricular free wall, papillary muscle rupture with acute mitral regurgitation and ventricular septal rupture. They are associated with an increased or, sometimes, with an extremely high mortality rate, determining the overall mortality in an MI patient population. In this review we summarize the mechanisms of MI complications, current therapeutic management and alternative directions for overcoming their devastating consequences. Moreover, we have sought to indicate gaps in the evidence on current treatments as the potential targets for further clinical research. From the perspective of mortality trends that are not improving, the forthcoming therapeutic management of complicated MI will require an individualized and novel approach based on their thorough pathobiology.

Mitral Regurgitation Following Acute Myocardial Infarction Treated by Percutaneous Coronary Intervention-Prevalence, Risk factors, and Predictors of Outcome

Mitral regurgitation (MR) following acute myocardial infarction (AMI) worsens prognosis and reports of prevalence vary significantly. The objective was to determine prevalence, risk factors, and outcomes related to MR following AMI. We identified 1000 consecutive patients admitted with AMI in 2016/17 treated by percutaneous coronary intervention with pre-discharge transthoracic echocardiography. MR was observed in 294 of 1000 (29%), graded as mild (n = 224 [76%]), moderate (n = 61 [21%]) and severe (n = 9 [3%]). Compared with patients without MR, patients with MR were older (70 ± 12 vs 63 ± 13 years; p <0.001), with worse left ventricular ejection fraction (LVEF) (52 ± 15% vs 55 ± 11%; p <0.001) and creatinine clearance (69 ± 33 ml/min vs 90 ± 39 ml/min; p <0.001). They also had higher rates of hypertension (64% vs 55%; p = 0.012), heart failure (3.4% vs 1.1%; p = 0.014), previous MI (28% vs 20%; p = 0.005) and severe flow-limitation in the circumflex (50% vs 33%; p <0.001) or right coronary artery (51% vs 42%; p = 0.014). Prevalence and severity of MR were unaffected by AMI subtype. Revascularization later than 72 hours from symptom-onset was associated with increased likelihood of MR (33% vs 25%; p = 0.036) in patients with non-ST elevation myocardial infarction (NSTEMI). After a mean of 3.2 years, 56 of 288 (19%) patients with untreated MR died. Age and LVEF independently predicted mortality. The presence of even mild MR was associated with increased mortality (p = 0.029), despite accounting for confounders. In conclusion, MR is observed in over one-quarter of patients after AMI and associated with lower survival, even when mild. Prevalence and severity are independent of MI subtype, but MR was more common with delayed revascularization following NSTEMI.

Safety and Feasibility of MitraClip Implantation in Patients with Acute Mitral Regurgitation after Recent Myocardial Infarction and Severe Left Ventricle Dysfunction

Patients with severe mitral regurgitation (MR) after myocardial infarction (MI) have an increased risk of mortality. Transcatheter mitral valve repair may therefore be a suitable therapy. However, data on clinical outcomes of patients in an acute setting are scarce, especially those with reduced left ventricle (LV) dysfunction. We conducted a multinational, collaborative data analysis from 21 centers for patients who were, within 90 days of acute MI, treated with MitraClip due to severe MR. The cohort was divided according to median left ventricle ejection fraction (LVEF)-35%. Included in the study were 105 patients. The mean age was 71 ± 10 years. Patients in the LVEF < 35% group were younger but with comparable Euroscore II, multivessel coronary artery disease, prior MI and coronary artery bypass graft surgery. Procedure time was comparable and acute success rate was high in both groups (94% vs. 90%, p = 0.728). MR grade was significantly reduced in both groups along with an immediate reduction in left atrial V-wave, pulmonary artery pressure and improvement in New York Heart Association (NYHA) class. In-hospital and 1-year mortality rates were not significantly different between the two groups (11% vs. 7%, p = 0.51 and 19% vs. 12%, p = 0.49) and neither was the 3-month re-hospitalization rate. In conclusion, MitraClip intervention in patients with acute severe functional mitral regurgitation (FMR) due to a recent MI in an acute setting is safe and feasible. Even patients with severe LV dysfunction may benefit from transcatheter mitral valve intervention and should not be excluded.

Native Coronary Collateral Microcirculation Reserve in Rat Hearts

Background We occasionally noticed that native collateral blood flow showed a recessive trend in the early stages of acute myocardial infarction in rats, which greatly interferes with the accurate assessment of native collateral circulation levels. Here, we sought to recognize the coronary collateral circulation system in depth, especially the microcirculation part, on this basis. Methods and Results In this study, we detected native collateral flow with positron emission tomography perfusion imaging in rats and found that the native flow is relatively abundant when it is initially recruited. However, this flow is extremely unstable in the early stage of acute myocardial infarction and quickly fails. We used tracers to mark the collateral in an ischemic area and a massive preformed collateral network was labeled. The ultrastructures of these collateral microvessels are flawed, which contributes to extensive leakage and consequent interstitial edema in the ischemic region. Conclusions An unrecognized short-lived native coronary collateral microcirculation reserve is widely distributed in rat hearts. Recession of collateral blood flow transported by coronary collateral microcirculation reserve contributes to instability of native collateral blood flow in the early stage of acute myocardial infarction. The immature structure determines that these microvessels are short-lived and provide conditions for the development of early interstitial edema in acute myocardial infarction.

Applying WCACG modified process is beneficial on reduced door-to-balloon time of acute STEMI patients

Background: Various systems have employed with the objective to reduce the time from emergency medical services contact to balloon inflammation for ST-elevation myocardial infraction (STEMI) patients. The WCACG message system was used to an alternative communication platform to improve confirmation of the diagnosis and movement to treatment, resulted in shorten the door-to-balloon (D-to-B) time for STEMI patients.

Methods: We collected 366 STEMI patients admitted at the Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People’s Hospital, Department of Cardiology, during the period from June 2013 to October 2015. The patients were divided into two groups one underwent the current GC processes and the other group was handled using WCACG system. We compared between two groups with several indicators including D-to-B time, duration of hospitalization, associated costs, and incidence of adverse cardiovascular events.

Results: The results show that the new method with WCACG system significantly reduced the average D-to-B time (from 100.42 ± 25.14 mins to 79.81 ± 20.51 mins, P < 0.05) compared to the GC processes, and also reduced the duration, costs and undesirable cardiac incidence during hospitalization.

Conclusions: The modified WCACG process is an applicable system to save pieces of time and efficiently integrate the opinions of experts in emergency.

Percutaneous coronary intervention for acute myocardial infarction with mitral regurgitation

Ischemic mitral regurgitation (IMR) is a common complication of acute myocardial infarction (AMI). Current evidences suggest that revascularization of the culprit vessels with percutaneous coronary artery intervention (PCI) or coronary artery bypass grafting can be beneficial for relieving IMR. A 2.5-year follow-up data of a 61-year-old male patient with ST-segment elevation AMI complicated with IMR showed that mitral regurgitation area increased five days after PCI, and decreased to lower steady level three months after PCI. This finding suggest that three months after PCI might be a suitable time point for evaluating the possibility of IMR recovery and the necessity of surgical intervention of the mitral valve for AMI patient.

Left Ventricular Mechanics in Functional Ischemic Mitral Regurgitation in Acute Inferoposterior Myocardial Infarction

Ischemic mitral regurgitation (MR) is an established adverse prognostic factor after myocardial infarction (MI). Functional ischemic mitral regurgitation in acute phase of MI remains under‐investigated due to its often transient and dynamic nature. We aimed to assess left ventricular (LV) mechanics by speckle‐tracking echocardiography in acute inferoposterior MI and ischemic mitral regurgitation (MR).

Methods

Sixty‐nine patients with no structural cardiac valve abnormalities and first acute inferoposterior MI were prospectively enrolled into the study. Two‐dimensional transthoracic echocardiography for regional myocardial function and valve assessment was performed within 48 hours of presentation after reperfusion therapy (percutaneous coronary intervention). Based on degree of MR, patients were divided into no significant MR (NMR) group (N = 34, with no or mild (grade 0–I) MR) and ischemic MR (IMR) group (N = 35, with grade ≥2 MR). Thirty‐five age‐ and gender‐matched healthy individuals served as a normal reference group. Offline 2D speckle tracking analysis was performed with GE EchoPAC software.

Results

LV ejection fraction and longitudinal myocardial deformation parameters were significantly better in healthy subjects, but did not differ between both study groups. All circumferential myocardial deformation parameters were significantly worse in IMR group compared to healthy subjects and NMR group. Global, basal, and mid‐ventricular radial strain was significantly lower in IMR group compared to both—healthy subjects and NMR group.

Conclusion

Ischemic mitral regurgitation in acute inferoposterior MI is associated with worse radial and circumferential LV deformation parameters assessed by 2D speckle tracking echocardiography.