António Fiarresga

Temporal variations in microvolt T-wave alternans testing after acute myocardial infarction.

Background: Microvolt T‐wave alternans (TWA) have been accepted as a tool for assessing vulnerability to ventricular tachyarrhythmias. There is lack of data concerning prospective temporal variations in TWA measurements after acute myocardial infarction (AMI). We analysed the temporal patterns of TWA in post‐AMI patients.

Percutaneous Occlusion of Vascular Malformations in Pediatric and Adult Patients: 20-Year Experience of a Single Center

A case series on different vascular malformations (VM) treated with percutaneous occlusion in children and adults is presented.

Intracoronary Delivery of Human Mesenchymal/Stromal Stem Cells: Insights from Coronary Microcirculation Invasive Assessment in a Swine Model.

Background Mesenchymal stem/stromal cells have unique properties favorable to their use in clinical practice and have been studied for cardiac repair. However, these cells are larger than coronary microvessels and there is controversy about the risk of embolization and microinfarctions, which could jeopardize the safety and efficacy of intracoronary route for their delivery. The index of microcirculatory resistance (IMR) is an invasive method for quantitatively assessing the coronary microcirculation status. Objectives To examine heart microcirculation after intracoronary injection of mesenchymal stem/stromal cells with the index of microcirculatory resistance. Methods Healthy swine were randomized to receive by intracoronary route either 30x106 MSC or the same solution with no cells (1% human albumin/PBS) (placebo). Blinded operators took coronary pressure and flow measurements, prior to intracoronary infusion and at 5 and 30 minutes post-delivery. Coronary flow reserve (CFR) and the IMR were compared between groups. Results CFR and IMR were done with a variance within the 3 transit time measurements of 6% at rest and 11% at maximal hyperemia. After intracoronary infusion there were no significant differences in CFR. The IMR was significantly higher in MSC-injected animals (at 30 minutes, 14.2U vs. 8.8U, p = 0.02) and intragroup analysis showed a significant increase of 112% from baseline to 30 minutes after cell infusion, although no electrocardiographic changes or clinical deterioration were noted. Conclusion Overall, this study provides definitive evidence of microcirculatory disruption upon intracoronary administration of mesenchymal stem/stromal cells, in a large animal model closely resembling human cardiac physiology, function and anatomy.

Terapêutica percutânea da insuficiência mitral: experiência inicial com o dispositivo MitraClip

INTRODUCTION Mitral regurgitation (MR) is the most common valvular disease and has recently become the target of a number of percutaneous approaches. The MitraClip is virtually the only device for which there is considerable experience, with more than 20,000 procedures performed worldwide. OBJECTIVE To describe our initial experience of the percutaneous treatment of MR with the MitraClip device. METHODS We describe the first six MitraClip cases performed in this institution (mean age 58.5 ± 13.1 years), with functional MR grade 4+ and New York Heart Association (NYHA) heart failure class III or IV (n=3), with a mean follow-up of 290 ± 145 days. RESULTS Procedural success (MR ≤ 2+) was 100%. Total procedure time was 115.8 ± 23.7 min, with no in-hospital adverse events and discharge between the fourth and eighth day, and consistent improvement in the six-minute walk test (329.8 ± 98.42 vs. 385.33 ± 106.95 m) and in NYHA class (three patients improved by two NYHA classes). During follow-up there were two deaths, in two of the four patients who had been initially considered for heart transplantation. CONCLUSION In patients with functional MR the MitraClip procedure is safe, with both a high implantation and immediate in-hospital success rate. A longer follow-up suggests that the clinical benefit decreases or disappears completely in patients with more advanced heart disease, namely those denied transplantation or on the heart transplant waiting list.

Short QT syndrome presenting as syncope: How short is too short?

We report the case of a 52-year-old man who presented to our emergency department (ED) after three episodes of syncope in the seven hours before admission. During his stay in the ED he had recurrent ventricular tachycardia (VT) requiring external electrical cardioversion. A 12-lead electrocardiogram (ECG) showed a short QT (SQT) interval (270 ms, QTc 327 ms), with frequent R-on-T extrasystoles triggering sustained polymorphic VT. After exclusion of other precipitating causes, the patient was diagnosed as having SQT syndrome (SQTS) according to the Gollob criteria. To our knowledge, this is the first known documentation of an SQT-caused arrhythmic episode on a 12-lead ECG, as well as the first reported case of SQTS in Portugal. The patient received an implantable cardioverter-defibrillator and was discharged. At a follow-up assessment 14 months later he was symptom-free, interrogation of the device showed no arrhythmic events, and the ECG showed a QT interval of 320 ms (QTc 347 ms).

Terapia celular cardíaca com células mesenquimatosas

Cardiovascular disease is among the main causes of mortality and morbidity worldwide. Despite significant advances in medical and interventional therapy, the prognosis of conditions such as ischemic heart disease is still dismal. There is thus a need to investigate new therapeutic tools, one of which is stem cell therapy. Hematopoietic stem cells are the most studied type, and the fact that their biology is relatively well understood has led to their being used in preclinical research and clinical trials. However, the results of some of these studies have been controversial, which has opened the way for studies on other cell types, such as mesenchymal stem cells. These cells have immunomodulatory properties which suggest that they have therapeutic potential in cardiology. In the present article, the authors review the state of the art regarding mesenchymal stem cells, from basic and translational research to their use in clinical trials on ischemic heart disease, heart failure and arrhythmias, and discuss possible future uses.

Safety and Effectiveness of the Genous™ Endothelial Progenitor Cell-Capture Stent in the First Year Following ST-Elevation Acute Myocardial Infarction: A Single Center Experience and Review of the Literature

PURPOSE The Genous™ stent (GS) is designed to accelerate endothelization, which is potentially useful in the pro-thrombotic environment of ST-elevation acute myocardial infarction (STEMI). We aimed to evaluate the safety and effectiveness of the GS in the first year following primary percutaneous coronary intervention (PCI) and to compare our results with the few previously published studies. METHODS AND MATERIALS All patients admitted to a single center due to STEMI that underwent primary PCI using exclusively GS, between May 2006 and January 2012, were enrolled. The primary study endpoints were major adverse cardiac events (MACEs), defined as the composite of cardiac death, acute myocardial infarction and target vessel revascularization, at one and 12 months. RESULTS In the cohort of 109 patients (73.4% male, 59 ± 12 years), 24.8% were diabetic. PCI was performed in 116 lesions with angiographic success in 99.1%, using 148 GS with median diameter of 3.00 mm (2.50-4.00) and median length of 15 mm (9-33). Cumulative MACEs were 2.8% at one month and 6.4% at 12 months. Three stent thromboses (2.8%), all subacute, and one stent restenosis (0.9%) occurred. These accounted for the four target vessel revascularizations (3.7%). At 12 months, 33.9% of patients were not on dual antiplatelet therapy. CONCLUSIONS GS was safe and effective in the first year following primary PCI in STEMI, with an apparently safer profile comparing with the previously published data. SUMMARY We report the safety and effectiveness of the Genous™ stent (GS) in the first year following primary percutaneous coronary intervention in ST-elevation acute myocardial infarction. A comprehensive review of the few studies that have been published on this subject was included and some suggest a less safe profile of the GS. Our results and the critical review included may add information and reinforce the safety and effectiveness of the GS in ST-elevation in acute myocardial infarction.

Power of Contemporary Clinical Strategies to Detect Patients withObstructive Coronary Artery Disease

Background: Non-invasive Ischemia Testing (NIST) is recommended for most patients suspected to have stable coronary artery disease (CAD) before invasive cardiac angiography (ICA). We sought to assess the diagnostic predictive ability of NIST over clinical risk profiling in a contemporary sample of patients undergoing the currently recommended diagnostic triage strategy. Methods and results: From 2006 - 2011, 2600 consecutive patients without known CAD undergoing elective ICA in a single tertiary - care centre were retrospectively identified and the prevalence of obstructive CAD determined. To understand the incremental value of frequently used clinical parameters in predicting obstructive CAD, receiver - operating - characteristic curves were plotted for six sequential models starting with Framingham risk score and then progressively adding multiple clinical factors and finally NIST results. At ICA 1268 patients (48.8%) had obstructive. The vast majority (85%) were classified in an intermediate clinical pre - test probability of CAD and NIST prior to ICA was used in 86% of the cohort. The most powerful correlate of obstructive CAD was the presence of severe angina (OR = 9.1, 95% confidence interval (CI), 4.3 - 19.1). Accordingly, the incorporation of NIST in a sequential model had no significant effect on the predictive ability over that achieved by clinical and symptomatic status model (C - statistic 0.754; 95% CI, 0.732 - 0.776, p = 0.28). Conclusions: Less than half the patients with suspect stable obstructive CAD referred to a tertiary level centre for elective ICA had the diagnosis confirmed. In this clinical setting, the results of NIST may not have the power to change the discriminative ability over clinical judgment alone.

Yield of contemporary clinical strategies to detect patients with obstructive coronary artery disease

Purpose Noninvasive ischemia testing (NIST) is recommended for most patients suspected to have stable coronary artery disease (CAD) before invasive coronary angiography (ICA). We sought to assess the diagnostic predictive ability of NIST over clinical risk profiling in a contemporary sample of patients undergoing the currently recommended diagnostic triage strategy. Methods From 2006 to 2011, 2,600 consecutive patients without known CAD undergoing elective ICA in a single tertiary-care center were retrospectively identified and the prevalence of obstructive CAD determined. To understand the incremental value of frequently used clinical parameters in predicting obstructive CAD, receiver operating characteristic curves were plotted for six sequential models starting with Framingham risk score and then progressively adding multiple clinical factors and finally NIST results. Results At ICA 1,268 patients (48.8%) had obstructive CAD. The vast majority (85%) were classified in an intermediate clinical pretest probability of CAD and NIST prior to ICA was used in 86% of the cohort. The most powerful correlate of obstructive CAD was the presence of severe angina (odds ratio (OR) = 9.1; 95% confidence interval (CI) 4.3-19.1). Accordingly, the incorporation of NIST in a sequential model had no significant effect on the predictive ability over that achieved by clinical and symptomatic status model (C-statistic 0.754; 95% CI 0.732-0.776, p = 0.28). Conclusions Less than half the patients with suspect stable obstructive CAD referred to a tertiary-level center for elective ICA had the diagnosis confirmed. In this clinical setting, the results of NIST may not have the power to change the discriminative ability over clinical judgment alone.

Cardiogenic shock in acute myocardial infarction: Stratify to prevent

Cardiogenic shock (CS) is defined as persistent hypotension (systolic blood pressure <90 mmHg) secondary to myocardial dysfunction, associated with signs of organ hypoperfusion. CS may be present in 10% of patients with ST-segment elevation myocardial infarction (STEMI) and is associated with 30-day mortality of about 50%. In the majority of STEMI patients, hemodynamic deterioration occurs after hospital admission, which means that there may be room for preventive measures and highlights the importance of early recognition of those most likely to evolve to CS. Scores such as Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC), Thrombolysis in Myocardial Infarction (TIMI), the Global Registry of Acute Coronary Events (GRACE) and the Zwolle risk score are used to stratify patients and enable the adoption of different levels of clinical monitoring, therapeutic care and post-discharge strategies. However, the search for simpler and more accurate scores has continued. The shock index (SI) is defined as the ratio of heart rate to systolic blood pressure, and was introduced in