Evaluation of transient apical ballooning with cardiac magnetic resonance imaging and 31-phosphorous magnetic resonance spectroscopy

Stress-induced cardiomyopathy (Tako-Tsubo syndrome) in Austria

BACKGROUND

Tako-Tsubo syndrome (TS) is a still rarely diagnosed clinical syndrome, which is characterized by acute onset of chest pain, transient cardiac dysfunction with (frequently) reversible wall motion abnormalities (WMAs), but with no relevant obstructive coronary artery disease.

METHODS AND RESULTS

Among 179 consecutive patients with proven diagnosis of TS that were retrospectively analysed in this multicentre registry, women represented the majority of patients (94%) while only 11 men (6%) developed TS. Mean age was 69.1±11.5 years (range 35-88 years). Cardinal symptoms of TS, which led to admission, were acute chest pain (82%) and dyspnoea (32%), respectively. All patients demonstrated typical WMAs, whereby four different types of WMAs could be defined: (1) a more common apical type of TS (n=89; 50%); (2) a combined apical and midventricular form of TS (n=23; 13%); (3) the midventricular TS (n=6; 3%); and (4) an unusual type of basal WMAs of the left ventricle (n=3). Only in 101 patients (57%), a clear causative trigger for onset of symptoms could be identified. In-hospital cardiovascular complications occurred in 25 patients (14%) and consisted of cardiac arrhythmias in 10 patients (40%), cardiogenic shock in six patients (24%), cardiac decompensation in eight patients (32%) and cardiovascular death in one patient, respectively. Echocardiographic control of left ventricular function after the initial measurement was available in almost 70% of the patients: complete recovery of WMAs was found in 73 patients (58.87%); 49 patients (39.52%) showed persistent WMAs. Recurrences of TS were only seen in four patients. During the follow-up period, 13 patients died: three of cardiovascular causes and 10 of non-cardiac causes. In-hospital mortality was 0.6%, 30-day mortality was 1.3% and 2-year mortality was 6.7%.

CONCLUSIONS

This study represents to date the largest series of patients suffering from TS in Austria and worldwide. Similar to others, in our series the prevalence of TS was significantly higher in women than in men, while in contrast to other studies, the apical type of TS was detected most frequently. The similar clinical presentation of TS patients to the clinical picture of acute myocardial infarction demonstrates the importance of immediate coronary angiography for adequate differential diagnosis of TS. TS is not necessarily a benign disease due to cardiovascular complications as well as persistent WMAs with delayed recovery.

Assessing myocardial recovery following ST-segment elevation myocardial infarction: short- and long-term perspectives using cardiovascular magnetic resonance

Myocardial recovery after revascularization for ST-segment elevation myocardial infarction (STEMI) remains a significant diagnostic and, despite novel treatment strategies, a therapeutic challenge. Cardiovascular magnetic resonance (CMR) has emerged as a valuable clinical and research tool after acute STEMI. It represents the gold standard for functional and morphological evaluation of the left ventricle. Gadolinium-based perfusion and late-enhancement viability imaging has expanded our knowledge about the underlying pathologies of inadequate myocardial recovery. T2-weighted imaging of myocardial salvage after early reperfusion of the infarct-related artery underlines the effectiveness of current invasive treatment for STEMI. In the last decade, the number of publications on CMR after acute STEMI continued to rise, with no plateau in sight. Currently, CMR research is gathering robust prognostic data on standardized CMR protocols with the aim to substantially improve patient care and prognosis. Beyond established CMR protocols, more specific methods such as magnetic resonance relaxometry, myocardial tagging, 4D phase-contrast imaging and novel superparamagnetic contrast agents are emerging. This review will discuss the currently available data on the use of CMR after acute STEMI and take a brief look at developing new methods currently under investigation.

Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance

BACKGROUND

Early and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months).

METHODS

STEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization.

RESULTS

Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012).

CONCLUSION

Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.

[Magnetic resonance tomography and spectroscopy investigations of the human heart]

The use of cardiac magnetic resonance (CMR) has emerged in the last decades. Technical innovations provide fast and high-quality imaging sequences and CMR is often proposed as a gold-standard for the in vivo evaluation of cardiac function, morphologic details and infarct size. Also the 31-phosphorous magnetic resonance spectroscopy (MRS) is a unique tool to investigate the human myocardial high-energy phosphate (HEP) metabolism in vivo. PCr/b-ATP ratio examined by MRS is mainly used as an index for cardiac energy metabolism. We have described decreased PCr/b-ATP ratios in patients with diabetes mellitus, hypercholesterolemia and hemochromatosis. The use of CMR to study the effects of ischemia time on the evolution of myocardial infarct characteristics after an acute myocardial infarction (AMI) treated with a primary angioplasty (p-PTCA) is a promising new application of this technique. Results of this study will further help to clarify the impact of ischemia time on myocardial regional functional recovery after p-PTCA.