AMI causing cardiogenic shock in patients with severely depressed left ventricular function

Introduction

Left ventricular function is assumed to be the main predictor of cardiogenic shock (CS), however trials and registries show that in average left ventricular function is only moderately depressed in CS after acute myocardial infarction.

Purpose

Characterize population of patients (Pts) with CS after acute myocardial infarction (AMI) and with severe left ventricular dysfunction (defined as ejection fraction (EF) <30%).

Methods

From a national multicenter registry, we evaluated 729ptswith CS after AMI.We considered 2 groups: Group 1 – pts with CS and EF <30% and Group 2 – pts with CS and EF >30%. We registered age, gender, cardiovascular and non-cardiovascular comorbidities, electrocardiographic presentation, vital signs at admission, reperfusion strategy and coronary anatomy. We also evaluated in-hospital complications, such as re-infarction, mechanical complications, high-grade atrial ventricular block, sustained ventricular tachycardia (VT), atrial fibrillation (AF) and stroke. We compared in-hospital mortality and multivariate analysis was performed to assess the impact of EF in in-hospital mortality and to identify predictors of severe left ventricular function.

Results

Severe dysfunction in Cardiogenic shock due to AMI was present in 28.9% (n=211) of pts (68% male, mean age of 72±12 years old). Group 1 had higher incidence of previous heart disease, such as AMI, previous PCI and congestive heart failure (27% vs 14%, p<0.001; 17.7% vs 9.6% p=0.002 and 16% vs 10%, p=0.022, respectively). STEMI pts were 71% (n=149), and timing from symptoms until first contact was longer (185 min (90; 437) vs 123 (60; 300), p<0.001). Undetermined location AMI was more often in group 1 (8% vs 2%, p<0.001), particularly due to left or right bundle brunch block (13% vs 4.7%, p<0.001, and 15% vs 10%, p=0.041 respectively). Anterior STEMI was also more prevalent in this groups (81% vs 46%, p<0.001). No differences were observed on coronariography rate, rate or type of reperfusion nor multivessel disease. Group 1 pts presented more with left main (LM) (25% vs 12%, p<0.001) and anterior descending (AD) (9.4% vs 2.4%, p<0.001) arteries lesions (88% vs 72.4%, p<0.001) or occlusion (65.5% vs 33.7%, p<0.001). Group 1 presented more with in-hospital VT (16% vs 10.8%, p=0.048). In-hospital mortality was also higher (56.5% vs 29.5%, p<0.001). After multivariate analysis we found that severe left ventricular dysfunction was a mortality predictor (OR 3.37; 95% CI 2.05–5.54, p<0.001). LM (OR 3.41; 95% CI 1.86–6.26, p<0.001) and AD (OR 2.74; 95% CI 1.51–4.96, p=0.001) arteries disease and previous AMI (OR 2.36; 95% CI 1.28–4.37, p=0.006) were predictors of severe LV dysfunction.

Conclusions

Severely depressed EF is a predictor of in-hospital mortality. Left main and anterior descending artery disease and previous AMI were identified as predictors of an EF <30%.

Funding Acknowledgement

Type of funding sources: None.

Cardiac magnetic resonance evaluation of takotsubo cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Takotsubo Cardiomyopathy(TCM)is a reversible pathology with clinical features practically indistinguishable from AMI.Cardiac magnetic resonance(CMR)is uniquely suited in differentiating TCM from other forms of acute ventricular dysfunction.CMR can also identify potential complications.

Purpose

The aim of this study was to characterize TCM features,as well as to evaluate diagnostic and prognostic impact of CMR in these patients.

Methods

A 7-years prospective study,which included patients of our center proposed to CMR with presumptive diagnosis of MINOCA based on acute chest pain,troponin raise and absence of angiographically significant coronary disease (luminal stenosis <50%).We analysed clinical characteristics, electrocardiograms, echo and coronariography.A presumptive diagnosis was elaborated and comparison was made with the TCM definitive one after CMR.We applied a protocol to evaluate TCM patients’ left and right ventricles(LV;RV)both anatomically and functionally, and search for late gadolinium enhancement(LGE).

Results

A total of 93 patients were evaluated,of which 16 had the final diagnosis of TCM.Takotsubo-cardiomyopathy patients were all female,with a mean age of 69 ± 14years old.At admission,75% had ST segment elevation, so emergent coronariography was performed. The median highest troponin I was 2,235[1,30-4,27]ng/mL.CMR confirmed 25%(n = 4) of presumptive diagnosis of TCM. On the other 75%initial diagnosis was changed to TCM after CMR:50%(n = 6) and 17%(n = 2)of patients had an initial presumptive diagnoses of reperfunded STEMI and NSTEMI,respectively. In 33% the initial diagnosis was myocarditis.From CMR evaluation of TCM patients, left atrial dilation was found in 31%(mean indexed area 18 ± 1,5cm2/m2).A majority (81%) presented with preserved ejection fraction(EF)(mean LV EF 59 ± 10%).Regional contractility abnormalities were described in 19%,being hypokinesia in all mid and apical segments in 2 cases, and diffuse in one.LV dysfunction was present in 13%(mean LV EF 32 ± 2%) and RV"s in 2cases (mean RV EF 42%),with only one with biventricular EF depression.Mean LV end diastolic indexed volume(EDIV)was 72 ± 23mL/m2,with only 2 with LV dilation(LV EDIV 120 ± 7mL/m2),non had dilated RV.Mild pericardial effusion was found in 38%,mild mitral regurgitation in 8patients and moderate in 1.A complication was registered:LV outflow tract protomesossystolic acceleration with mild anterior leaflet prolapse,without SAM.No LV thrombus was identified.LGE was observed in 2(13%)of patients:in one it was found on the apex,on the other one the pattern was linear intramyocardial on mid segment of inferior septum.

Conclusion

CMR provides a noninvasive and multidimensional assessment for evaluation of Takotsubo cardiomyopathy.In our population,performing CMR allowed an initial diagnosis modification in 3/4 of the cases and identification of one complication,both with therapeutic and prognostic implications.

Cardiac Magnetic Resonance as a diagnostic tool in arrhythmias

Funding Acknowledgements

Type of funding sources: None.

Introduction

Etiology of cardiac arrhythmias is often difficult to determine.As the gold standard to anatomical and functional cardiac evaluation,Cardiac Magnetic Resonance(CMR)can be a fundamental technique for accurate assessment of myocardial arrhythmic substrates or for arrhythmias management.

Purpose

The aim of this study is to determine diagnostic and arrhythmic risk stratification impact of CMR performed in patients with suspected or confirmed arrhythmias.

Methods

We performed a six-years prospective study of patients with suspected or confirmed arrhythmias which evaluation with other techniques did not provide a definitive diagnosis.These patients underwent CMR for diagnostic and risk stratification assessment.We applied a protocol to evaluate both ventricles’ morphology and functional and late gadolinium enhancement (LGE) presence.

Results

A total of 93 patients were included,of which 66% were male, with a mean age of 45 ± 17 years old. The indications for patients with suspected or confirmed arrhythmias performing CMR evaluation were the following: 33% (n = 31) of the patients had very frequent premature ventricular complexes, 23% (n = 21) had sustained ventricular tachycardia (VT), 5%(n = 5) non-sustained VT, 17%(n = 16) suspected structural heart disease with high arrhythmic potential,10%(n = 9) unexplained recurrent syncope,9 %(n = 8) supraventricular tachycardia and 3% (n = 3) aborted sudden cardiac death. Depressed ejection fraction (EF)(<50%) was present in 10% (n = 9) for LV(mean EF 38 ± 9%) and 15%(n = 14) for RV (mean EF 42 ± 7%). Dilation of LV was found in 25% of patients (n = 23, mean LV volume: 115 ± 7ml/m²), with RV dilation being present in only 1 patient, who had right ventricle arrhythmogenic dysplasia (RVAD) (RV volume: 152ml/m²). In total, 16%had interventricular septum hypertrophy (mean 15 ± 4mm/m2).We found slight anterior leaflet prolapse of mitral valve in 10% (n = 9) of the cases and mild mitral regurgitation in 15% (n = 14). Left atrium dilation was observed in 17% (n = 16) of patients (mean area of 18 ± 2cm2/m2), as right atrium was dilated in only two. In 20% of the patients, CMR contributed to establish a previously unknown diagnosis: 6% (n = 5) have hypertrophic cardiomyopathy,4%(n = 4)a myocarditis sequelae and 2%(n = 2)had RVAD. LV non-compaction,a silent myocardial infarction scar and non-ischemic dilated cardiomyopathy were diagnosed in 3%of the cases each. In 15%(n = 14)we found nonspecific variations, which deserve follow-up. On the remaining patients, CMR was considered normal.

Conclusion

 As a high reproducible, accurate and versatile technique, CMR allowed an increase on diagnosis in 20% of the patients with suspected or confirmed arrhythmias. Consequently, it contributed to the risk stratification of our study population with suspected high arrhythmic potential when the first-line complementary exams were inconclusive.

Comparing single approaches success in index atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial Fibrillation (AF) ablation can be performed by inducing pulmonary vein electrical isolation. There are two widely used approaches: point-by-point and single-shot.  Catheter AF ablation is effective in restoring and maintaining sinus rhythm. However, efficacy is limited by high rate of AF recurrence, after an initially successful procedure.

Purpose

To evaluate AF index ablation successfulness using single-shot techniques and compare them to conventional one (point-by-point using irrigated- tip ablation catheter).

Methods

We analyzed, from a single center, all patients submitted to an index AF ablation procedure and its successfulness. The last was defined as AF, atrial tachycardia or flutter recurrence (with a duration superior to 30seconds) event- free survival, determined by holter and/or event recorder. These exams were performed after 6 and 12months and then annually, until 5years post procedure were accomplished.

Results

From November 2004 to November 2020, 821patients were submitted to first AF ablation (male patients 67,2%(N = 552), mean age of 59 ± 12years old). Paroxysmal AF(PAF) was present in 62,9%(N = 516), with short-duration persistent AF in 21,8%(N = 179) and long-standing persistent in 15,3%(N = 126). Ablation techniques were irrigated tip catheter point-by-point (PbP)ablation in 266 patients (32,4%) and single-shot (SS)techniques on the remaining 555(67,6%), including PVAC in 294(35,8%),225(27,4%) submitted to cryoablation and 36(4,4%) to nMARQ.

Globally, AF ablation had one-year success rate of 72,5%, and 56,2% at 3 years. A significant difference between AF duration type was found: Arrhythmic recurrence risk was 58% higher in persistent AF(PeAF) (HR 1.58;95%IC 1,22-2,04; p < 0.001). In patients presenting with PAF prior to the procedure, success was significantly higher in those submitted to SS technique(HR:0.69;95%CI 0,47-0,90;p = 0.046), while those with PeAF had similar results.

Conclusion

In this single center analysis almost three-quarters had achieved one-year event-free survival, and more than a half reached long-term freedom from atrial arrhythmia. Patients with paroxysmal atrial fibrillation submitted to single-shot procedure presented with a higher success-rate. Moreover, our study confirmed previous data on the importance of atrial fibrillation classification to postprocedural outcomes. Abstract Figure. Survival Curves

Searching for the final diagnosis using cardiac magnetic resonance in MINOCA patients

Introduction

In patients with clinical evidence of acute myocardial infarction (AMI), absence of obstructive coronary disease does not imply absence of acute thrombotic process. Thereafter, it can be designated as Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA). In these cases, performing Cardiac Magnetic Resonance (CMR) can be essential for establishing a final diagnosis, due to evaluation of the presence and pattern of late enhancement.

Purpose

The aim of this study is to evaluate the diagnostic and prognostic impact of cardiac magnetic resonance in patients with a possible diagnosis of MINOCA.

Methods

A 7-years prospective study in our centre, which included all patients proposed to CMR with a presumptive diagnosis of MINOCA due to acute chest pain, troponin raise and absence of angiographically significant coronary disease (luminal stenosis of <50%). All patients performed functional, anatomical evaluation, as so late gadolinium enhancement search. We analysed clinical characteristics, electrocardiographic presentation, echocardiographic and coronariography results. A presumptive diagnosis was elaborated after coronariography and comparison was made with the definitive one after CMR.

Results

A total of 85 patients were included, 53% were male, with a mean age of 49±20 years old. Clinical history of hypertension was observed in 52% patients, 34% had dyslipidaemia, 8% with diabetes, obesity was present in 21% of patients and smoking habits in 33%. At admission, 47% had ST segment elevation, so emergent coronariography was performed. The mean highest troponin I was 7,54±9,39ng/mL. Late gadolinium enhancement was observed in 50 (59%) of patients. After CMR realization a final diagnosis of MINOCA was made in only 13 patients (15%) and in 51 patients (60%) CMR evaluation allowed a diagnosis modification, with impact on patients' management and prognosis. Of these 51 patients, a definitive diagnosis of myocarditis was seen in 65% of cases, of Takotsubo's myocardiopathy in 27%, and hypertrophic cardiomyopathy in 8%. In 21 (25%) of patients, late gadolinium enhancement was not found. However its absence could exclude type 1 AMI as definitive diagnosis.

Conclusion

CMR is a fundamental technique on MINOCA patients' management. In our population, performing CMR allowed initial diagnosis modification in about two thirds of the cases, with important therapeutic and prognostic implications.

Funding Acknowledgement

Type of funding source: None