Sorin Giusca

Prediction of functional recovery by cardiac magnetic resonance feature tracking imaging in first time ST-elevation myocardial infarction. Comparison to infarct size and transmurality by late gadolinium enhancement

PURPOSE To investigate whether myocardial deformation imaging, assessed by feature tracking cardiac magnetic resonance (FTI-CMR), would allow objective quantification of myocardial strain and estimation of functional recovery in patients with first time ST-elevation myocardial infarction (STEMI). METHODS Cardiac magnetic resonance (CMR) imaging was performed in 74 consecutive patients 2-4 days after successfully reperfused STEMI, using a 1.5T CMR scanner (Philips Achieva). Peak systolic circumferential and longitudinal strains were measured using the FTI applied to SSFP cine sequences and were compared to infarct size, determined by late gadolinium enhancement (LGE). Follow-up CMR at 6 months was performed in order to assess residual ejection fraction, which deemed as the reference standard for the estimation of functional recovery. RESULTS During the follow-up period 53 of 74 (72%) patients exhibited preserved residual ejection fraction ≥50%. A cut-off value of -19.3% for global circumferential strain identified patients with preserved ejection fraction ≥50% at follow-up with sensitivity of 76% and specificity of 85% (AUC=0.86, 95% CI=0.75-0.93, p<0.001), which was superior to that provided by longitudinal strain (ΔAUC=0.13, SE=0.05, z-statistic=2.5, p=0.01), and non-inferior to that provided by LGE (ΔAUC=0.07, p=NS). Multivariate analysis showed that global circumferential strain and LGE exhibited independent value for the prediction of preserved LV-function, surpassing that provided by age, diabetes and baseline ejection fraction (HR=1.4, 95% CI=1.0-1.9 and HR=1.4, 95% CI=1.1-1.7, respectively, p<0.05 for both). CONCLUSIONS Estimation of circumferential strain by FTI provides objective assessment of infarct size without the need for contrast agent administration and estimation of functional recovery with non-inferior accuracy compared to that provided by LGE.

Standardized assessment of global longitudinal and circumferential strain - a modality independent software approach

Mean GLS values were -16.2±5.3% and -17.3±5.3% for echocardiography and CMR, respectively. GLS did not differ significantly between the two imaging modalities, which showed strong correlation (r=0.86), a small bias (-1.1%) and narrow 95% limits of agreement (LOA, ±5.4%). Mean GCS values were -17.9±6.3% and -24.4 ±7.8% for echocardiography and CMR, respectively. GCS was significantly underestimated by echocardiography (p<0.001). A weaker correlation (r=0.73), a higher bias (-6.5%) and wider LOA (±10.5%) were observed for GCS. GLS showed a strong correlation (r=0.92) when image quality was good, while correlation dropped to r=0.82 with poor acoustic windows in echocardiography. GCS assessment revealed only a strong correlation (r=0.87) when echocardiographic image quality was good. No significant differences for GLS between two different echocardiographic vendors could be detected. Conclusions Quantitative assessment of GLS using a standardized software algorithm allows the direct comparison of values acquired irrespective of the imaging modality. GLS may therefore serve as a reliable parameter for the assessment of global left ventricular function in clinical routine besides standard evaluation of the ejection fraction.

Cardiac magnetic resonance and computed tomography angiography for clinical imaging of stable coronary artery disease. Diagnostic classification and risk stratification

Despite advances in the pharmacologic and interventional treatment of coronary artery disease (CAD), atherosclerosis remains the leading cause of death in Western societies. X-ray coronary angiography has been the modality of choice for diagnosing the presence and extent of CAD. However, this technique is invasive and provides limited information on the composition of atherosclerotic plaque. Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) have emerged as promising non-invasive techniques for the clinical imaging of CAD. Hereby, CCTA allows for visualization of coronary calcification, lumen narrowing and atherosclerotic plaque composition. In this regard, data from the CONFIRM Registry recently demonstrated that both atherosclerotic plaque burden and lumen narrowing exhibit incremental value for the prediction of future cardiac events. However, due to technical limitations with CCTA, resulting in false positive or negative results in the presence of severe calcification or motion artifacts, this technique cannot entirely replace invasive angiography at the present time. CMR on the other hand, provides accurate assessment of the myocardial function due to its high spatial and temporal resolution and intrinsic blood-to-tissue contrast. Hereby, regional wall motion and perfusion abnormalities, during dobutamine or vasodilator stress, precede the development of ST-segment depression and anginal symptoms enabling the detection of functionally significant CAD. While CT generally offers better spatial resolution, the versatility of CMR can provide information on myocardial function, perfusion, and viability, all without ionizing radiation for the patients. Technical developments with these 2 non-invasive imaging tools and their current implementation in the clinical imaging of CAD will be presented and discussed herein.

Incremental value of cardiac magnetic resonance for the evaluation of cardiac tumors in adults: experience of a high volume tertiary cardiology centre

To assess the value of cardiac magnetic resonance imaging (CMR) in evaluating cardiac tumours in a tertiary cardiology centre. Between 2004 and 2014, 125 patients (pts.) from a total of 17000 who received a CMR examination in our institution were referred with the suspicion of cardiac tumours. A dedicated protocol was used that included standard cine SSFP acquisitions as well as tissue characterization using T1 and T2 black-blood (T1 BB and T2 BB respectively) with and without fat suppression, perfusion of the structure and late gadolinium enhancement. Patients’ files were retrospectively analysed and data related to clinical status, results from other examinations (echocardiography), therapeutic approach and histology results, when performed, were collected. In 65 pts., a diagnosis of cardiac tumour was reached. 45 Pts had a biopsy. The CMR examination was concordant with the histology results in 35 (76%) pts. superior to that showed by echocardiography, 26 (58%) pts., p = 0.03. Forty-two (65%) pts. had a benign tumour and 23 (35%) a malignant process. Myxoma was the most frequent benign tumour, 27 (65%) and cardiac metastases were the most frequent form of malignancies, 21 (91%), with B cell non-Hodgkin lymphoma being the most frequent one, 4 (19%). Benign tumours were mostly located in the left atrium, 27 (64%) versus 6 (26%), p = 0.007, whereas malignant tumours had a predilection for the right atrium und left ventricle [11 (48%) vs. 3 (7%), p = 0.001 and 8 (35%) vs. 3 (7%), p = 0.03]. All benign cardiac tumours were single and did not show signs of infiltration. Conversely, malignant cardiac tumours were larger (43 ± 35 vs. 24 ± 16, p = 0.007) with a significant proportion (65%) showing myocardial infiltration. Pts with malignant cardiac tumours had a higher proportion of LGE (82 vs. 60%, p = 0.05) and exhibited more frequently an isointense signal in T1 BB images (78 vs. 61%, p = 0.04). Both groups showed similar proportion of perfusion and signal intensity in the T2 BB acquisitions (p = NS). CMR is a valuable tool in evaluating cardiac tumours, proving superior to echocardiography in establishing the type of cardiac tumour.

Aborted Sudden Cardiac Death in a Female Patient Presenting with Takotsubo-Like Cardiomyopathy due to Epicardial Coronary Vasospasm

Takotsubo cardiomyopathy is characterized by apical ballooning of the left ventricle (LV) in the absence of relevant coronary artery stenosis, which typically occurs in elderly women after emotional stress. Catecholamine cardiotoxicity, metabolic disturbance, and coronary microvascular impairment have previously been proposed as underlying pathophysiologic mechanisms of takotsubo cardiomyopathy, whereas myocardial stunning resulting from epicardial coronary artery vasospasm is not generally accepted as a cause of takotsubo cardiomyopathy. The prognosis of takotsubo cardiomyopathy is generally more favourable compared to myocardial infarction; however, severe complications such as rupture of the LV and life-threatening arrhythmias may occur. Herein, we describe a case of an 84-year-old female, who presented with aborted sudden cardiac death due to ventricular fibrillation. Echocardiography suggested LV apical ballooning with severely impaired LV-function, so that takotsubo cardiomyopathy was suspected. However, coronary angiography revealed epicardial spasm of the left anterior ascending, which resolved after intracoronary injection of 0.2 mg nitroglycerine. Cardiac magnetic resonance exhibited subendocardial late enhancement and echocardiography showed normalization of LV dysfunction during follow-up. The patient was put on conservative treatment with nitrates and calcium inhibitors and ICD implantation were deferred.

Ischemic Burden and Clinical Outcome: Is One ‘Culprit’ Ischemic Segment by Dobutamine Stress Magnetic Resonance Predictive?

Aims We sought to evaluate the impact of ischemic burden for the prediction of hard cardiac events (cardiac death or nonfatal myocardial infarction) in patients with known or suspected CAD who undergo dobutamine stress cardiac magnetic resonance imaging (DCMR) Methods We included 3166 patients (pts.), mean age 63±12 years, 27% female, who underwent DCMR in 3 tertiary cardiac centres (University Hospital Heildelberg, German Heart Institute and Kings College London). Pts. were separated in groups based on the number of ischemic segments by wall motion abnormalities (WMA) as follows: 1. no ischemic segment, 2. one ischemic segment, 3. two ischemic segments and 4. ≥three ischemic segments. Cardiac death and nonfatal myocardial infarction were registered as hard cardiac events. Pts. with an “early” revascularization procedure (in the first three months after DCMR) were not included in the final survival analysis. Results Pts. were followed for a median of 3.1 years (iqr 2–4.5 years). 187 (5.9%) pts. experienced hard cardiac events. 2349 (74.2%) had no inducible ischemia, 189 (6%) had ischemia in 1 segment, 292 (9.2%) in 2 segments and 336 (10.6%) ≥3 segments. Patients with only 1 ischemic segment showed a high rate of hard cardiac events of ∼6% annually, which was 10-fold higher compared to those without ischemia (0.6% annually, p<0.001) but similar to those with 2 and ≥3ischemic segments (∼5.5% and ∼7%, p = NS). Conclusions The presence of inducible ischemia even in a single ‘culprit’ myocardial segment during DCMR is enough to predict hard cardiac events in patients with known or suspected CAD.

Successful endovascular treatment in patients with acute thromboembolic ischemia of the lower limb including the crural arteries

AIM To examine the efficacy and safety of the 6 French (6F) Rotarex®S catheter system in patients with acute limb ischemia (ALI) involving thromboembolic occlusion of the proximal and mid-crural vessels. METHODS The files of patients in our department with ALI between 2015 and 2017 were examined. In seven patients, the Rotarex®S catheter was used in the proximal segment of the crural arteries. Data related to the clinical examination, Doppler sonography, angiography and follow-up from these patients were further used for analysis. RESULTS Two patients (29%) had thrombotic occlusion of the common femoral artery, and the remaining five exhibited thrombosis of the superficial femoral artery and popliteal artery. Mechanical thrombectomy was performed in all cases using a 6F Rotarex®S catheter. Additional Rotarex®S catheter thrombectomy due to remaining thrombus formation with no reflow was performed in the anterior tibial artery in two of seven cases (29%), in the tibiofibular tract and posterior tibial artery in two of seven cases (29%) and in the tibiofibular tract and fibular artery in the remaining three of seven cases (43%). Ischemic symptoms resolved promptly in all, and none of the patients experienced a procedural complication, such as crural vessel dissection, perforation or thrombus embolization. CONCLUSION Mechanical debulking using the 6F Rotarex®S catheter system may be a safe and effective treatment option in case of thrombotic or thromboembolic occlusion of the proximal and mid-portion of crural arteries.

Successful recanalization of long femoro-crural occlusive disease after failed bypass surgery

Patients with critical limb ischemia necessitate immediate intervention to restore blood flow to the affected limb. Endovascular procedures are currently preferred for these patients. We describe the case of an 80-year-old female patient who presented to our department with ischemic rest pain and ulceration of the left limb. The patient had history of left femoral popliteal bypass surgery, femoral thromboendarterectomy and patch angioplasty of the same limb 2 years ago. Doppler sonography and magnetic resonance angiography revealed an occlusion of the left superficial femoral artery (SFA) and popliteal artery and of all three infra-popliteal arteries. Due to severe comorbidities, the patient was scheduled for a digital subtraction angiography. An antegrade approach was first attempted, however the occlusion could not be passed. After revision of the angiography acquisition, a stent was identified at the level of the mid SFA, which was subsequently directly punctured, facilitating the retrograde crossing of the occlusion. Thereafter, balloon angioplasty was performed in the SFA, popliteal artery and posterior tibial artery. The result was considered suboptimal, but due to the large amount of contrast agent used, a second angiography was planned in 4 wk. In the second session, drug coated balloons were used to optimize treatment of the SFA, combined with recanalization of the left fibular artery, to optimize outflow. The post-procedural course was uneventful. Ischemic pain resolved completely after the procedure and at 8 wk of follow-up and the foot ulceration completely healed.

Successful carbon dioxide angiography guided endovascular thrombectomy of the superficial femoral artery in a young patient with critical limb ischemia.

Currently, the treatment of thromboembolic ischemia of the lower extremities includes percutaneous rotational thrombectomy and aspiration devices. However, the standard approach for endovascular treatment requires the administration of iodine contrast agents, which is problematic in patients with pre-existing renal disease and diabetes. Herein, we describe a case of a CO2 angiography guided endovascular thrombectomy of the superficial femoral artery (SFA) in a young patient with critical limb ischemia. Mechanical thrombectomy using the Rotarex system, catheter aided aspiration and subsequent stent placement in the SFA was entirely guided using CO2 angiography.

Image quality and contrast agent exposure in cardiac computed tomography angiography prior to transcatheter aortic valve implantation procedures using different acquisition protocols

Background ECG-gated cardiac computed tomography angiography (CCTA) has found widespread use for prosthesis sizing before transcatheter aortic valve implantation (TAVI). However, still little data exists on the optimal scan-strategy in such patients. We hypothesized that prospectively triggered CCTA can enable the visualization of aortic valve structures and peripheral arteries with lower radiation and contrast agent exposure in patients considered for TAVI compared to retrospectively gated protocols. Methods All studies were performed using a 256 multi-detector single source CT (iCT Philips, Best, Netherlands). With the prospective protocol the whole volume from the heart to the iliofemoral arteries scanned using prospective triggering. With the retrospective protocol a first retrospectively gated scan was performed for the heart and the iliofemoral part was subsequently scanned using a second non-triggered scan. Image quality was assessed semi-quantitatively and signal-to-noise- (SNR) and contrast-to-noise-ratios (CNR) were obtained for all scans. Results Prospective CCTA was performed in 74 and in 34 patients, respectively using non-tailored and BMI adapted scans, whereas retrospective CCTA was performed in 57 patients. Prospective scans required lower contrast agent administration compared to retrospective scans (71 ± 8 mL versus 91 ± 15 mL, p < 0.01) and resulted in lower radiation exposure (26 ± 7mSv for retrospective versus 15 ± 3mSv for non-tailored prospective versus 8 ± 4mSv for BMI-adapted prospective scans, p < 0.01). Visual image quality was better for the evaluation of aortic valve structures and similar for the assessment of iliofemoral anatomy with prospective versus retrospective scans. In addition, contrast density, SNR and CNR were higher in the ascending aorta with prospective versus retrospective CCTA (434 ± 98HU versus 349 ± 112HU; 35 ± 14 versus 24 ± 9 and 31 ± 11 versus 16 ± 7, p < 0.001 for all). Subsection analysis by heart rate groups demonstrated that both image quality and CNR were significantly higher in patients with prospective versus retrospective CCTA, irrespective of the heart rate during image acquisition. Conclusion Prospectively triggered CCTA allows for improved visualization of aortic valve structures and peripheral arteries in patients scheduled for TAVI with simultaneously reduced contrast agent dose and radiation exposure. Therefore, this acquisition mode seems to be the preferred for the evaluation of patients considered for TAVI.