Ischemic Wall Motion Research Articles

Feasibility of prehospital identification of non-ST-elevation myocardial infarction by ECG, troponin and echocardiography

BackgroundPrehospital identification and selection of treatment strategy in patients with suspected non-ST-elevation myocardial infarction (NSTEMI) is challenging. The aim of this study was to evaluate the feasibility and diagnostic accuracy...

The modified protocol of transesophageal atrial pacing in stress echocardiography as an alternative way to increase the information value of the method for detection of ischemic wall motion abnormalities

Aim To develop a new, modified protocol for transesophageal atrial electric stimulation (TEAES), which would significantly enhance the diagnostic value of stress echocardiography and reduce the duration of the test in patients with ischemic heart disease (IHD).Material and methods This study included 101 patients (80 men and 21 women aged 55±9 years) with suspected or documented diagnosis of IHD who were divided into two homogenous groups. Group 1 (51 patients) underwent stress echocardiography (stress-EchoCG) according to a standard protocol (SP) for TEAES and group 2 (50 patients), underwent stress-EchoCG according to a modified protocol (MP). In addition to stress-EchoCG with TEAES, selective coronary angiography was performed for all patients. The development of the new method for evaluating occult coronary insufficiency was based on comparison of SP and MP for TEAES with stress-EchoCG with data of coronary angiography.Results In both groups, significant differences in values of systolic and diastolic blood pressure were absent. However, the values of achieved heart rate were significantly different: 141±11 (TEAES SP) and 155±10 (TEAES MP) bpm (p=0.01). There was also a difference in the duration of the TEAES protocols: 15±3 and 5±2 min, respectively (p=0.006). The use of the modified TEAES protocol for detecting transient disorders of left ventricular myocardial local contractility increased the sensitivity, specificity and accuracy of the test from 76 %, 87 %, and 80 % to 83 %, 92 %, and 86 %, respectively. The most significant differences were found in the area supplied by the circumflex artery: the SP and MP sensitivities were 63 % and 75 %, respectively (p<0.05) and the SP and MP accuracies were 81 % and 90 %, respectively (p<0.05).Conclusion Evaluation of occult coronary insufficiency by stress-EchoCG with the TEAES MP as compared to the TEAES SP provides a gentler procedure regimen for the patient due to a shorter duration of the test and at the same time improves the diagnostic significance of this method in IHD patients.

The obesity paradox in the stress echo lab: fat is better for hearts with ischemia or coronary microvascular dysfunction.

Obesity is an independent risk factor for coronary artery disease (CAD), but once CAD has developed it has been associated with improved survival ("obesity paradox"). To assess how obesity affects prognosis in patients with or without inducible ischemic regional wall motion abnormalities (RWMA) and/or abnormal coronary flow velocity reserve (CFVR) during stress echocardiography (SE). In an observational retrospective two- center study design, we analyzed 3249 consecutive patients (1907 men; age 66 ± 12 years; body mass index, BMI, 26.9 ± 4.1 kg/m2) with known (n = 1306) or suspected (n = 1943) CAD who underwent dipyridamole SE with simultaneous evaluation of RWMA and CFVR. All-cause death was the outcome end-point. 1075 patients were lean (BMI 18.5-24.9 kg/m2), 1523 overweight (BMI 25.0-29.9 kg/m2), and 651 obese (≥30.0 kg/m2). Ischemic test result for RWMA occurred in 28 (3%) lean, 69 (4%) overweight, and 28 (4%) obese patients (p = 0.03). An abnormal CFVR (≤2.0) was found in 281 (26%) lean, 402 (26%) overweight and 170 (26%) obese patients (p = 0.99). During 68 ± 44 months of follow-up, 496 (15%) patients died. At multivariable Cox analysis, BMI ≥ 30 was an independent predictor of reduced mortality in the 878 patients with stress-induced (≥2 segments) RWMA and/or CFVR abnormality (HR 0.58, 95% CI 0.40-0.84; p = 0.003), while showed no effect at univariate analysis in the 2371 patients with no RWMA and normal CFVR (HR 1.04, 95% CI 0.74-1.46; p = 0.84). Obesity exerts a "paradoxical" protective effect in patients with stress-induced ischemia and/ or coronary microvascular dysfunction, and shows a neutral effect in patients with normal CFVR and no stress-induced RWMA.

P1506Pulmonary decongestion pattern during stress lung ultrasound

Abstract Background B-profile detected by lung ultrasound (LUS) during stress echocardiography (SE) consists in B-lines with lung sliding and mirrors extra-vascular lung water accumulation (“wet lung”), more often found with ischemic regional wall motion abnormalities (RWMA) and/or diastolic dysfunction. B-lines present at rest may also decrease during stress. Aim To assess the frequency and functional correlates of decreasing B-profile (“drying lung” pattern) during SE. Methods We prospectively performed transthoracic echocardiography (TTE) and LUS evaluation at rest and peak stress in 780 patients with B-lines at rest referred for exercise (n=387), vasodilator (n=324) or dobutamine (n=69) SE for known/suspected coronary artery disease (CAD) and/or heart failure (HF). Recruitment occurred in 17 certified labs of 8 countries with the ABCD protocol, including regional wall motion abnormalities with wall motion score index (WMSI), B-lines, left ventricular contractile reserve (LVCR based on force, systolic blood pressure/end-systolic volume) and Doppler-based coronary flow velocity reserve (CFVR, available in 473 patients). By LUS, we adopted the 4-site simplified scan, each site scored from 0=normal A-lines, to 10=coalescing B-lines. By selection, all patients had resting B-lines score ≥2. Invasive or noninvasive coronary angiography was available in 208 patients. Results Two B-lines stress patterns were identified: Group 1, increase or unchanged pattern (B-line stress score ≥ rest, n=698, 89%); Group 2, decrease-disappearance pattern (B-line stress score < rest for ≤2 points, n=82, 11%). Group 1 showed higher prevalence of inducible ischemia (Group 1 = 74/698 vs. Group 2 = 5/82, 11% vs. 6%, p<0.001), abnormal LVCR (Group 1 = 403/698 vs. Group 2 = 36/82, 58% vs. 42%, p=0.012) and impaired CFVR (Group 1 = 173/433 vs. Group 2 = 5/40, 40 vs. 12%, p<0.001): see figure. Two- or three-vessel coronary artery disease was also more frequent in fixed-worsening pattern (Group 1 = 88/191 vs. Group 2 = 3/17, 46 vs. 17%, p=0.024). Multivariate logistic regression analysis identified peak Force (Odds Ratio, OR, 1.039, 95% Confidence Intervals, CI: 1.006–1.074, P=0.022), stress-rest Δ-WMSI (OR 0.190, 95% CI 0.086–0.419, P<0.001) and normal CFVR (OR=1.754, 95% CI: 1.147–2.682, P=0.010) as significant predictors of drying lung pattern. Disappearing BLines Conclusion About one out of 10 patients with resting B-lines exhibit a decrease-disappearance pattern during stress. They show a more benign coronary anatomic, myocardial functional and coronary physiological profile compared to patients with the fixed-worsening pattern. The drying lung pattern is more often accompanied by a strong (higher peak force), non-ischemic and warm heart (with normal CFVR).

P4982Blunted heart rate reserve as an imaging-independent prognostic predictor during dipyridamole-echocardiography test

Abstract Background A blunted heart rate (HR) response during dipyridamole myocardial perfusion imaging have been associated with a poor outcome. Aim To assess the value of HR response in patients undergoing high dose dipyridamole stress echocardiography (SE). Methods We retrospectively selected a consecutive sample of 1,622 patients (none with pacemakers or atrial fibrillation), mean age 66±12 years, 431 (27%) on beta-blockers. All underwent high dose (0.84 mg/kg) dipyridamole SE for known or suspected coronary artery disease and/or heart failure from January 1988 to January 2018 in our Cardiology Division. HR (with 12-lead ECG) was obtained each minute and recorded at rest and peak stress. HR reserve (HRR) was calculated as the peak/rest HR ratio. All patients were followed-up. The composite end-point was made of all cause-death, non-fatal myocardial infarction and late (>3 months) symptoms-driven myocardial revascularizations. Results SE was positive for regional wall motion abnormalities (RWMA) in 192 patients (12%). HR increased (rest=70±11 beats/min vs stress= 92±17 beats/min, p<0.0001). During a median follow-up time of 904 days, 462 events occurred: 73 deaths, 57 non-fatal myocardial infarctions, 332 myocardial revascularizations. Receiver operating curve analysis identified a HRR ≤1.27 as the best cutoff. At multivariate analysis a reduced HRR was a significant predictor of hard events (Hazard Ratio, HR=2.02, 95% Confidence Intervals, CI, 1.38–2.95, P<0.0001), additive to ischemic regional wall motion abnormalities (HR=2.11, 95% CI 1.28–3.48, P=0.004), resting RWMA (HR =1.88, 95% CI 1.31–2.72, P<0.001), age (HR =1.06, 95% CI 1.04–1.08, P<0.001) and beta-blockers at the time of testing (HR =1.55, 95% CI 1.06–2.29, P=0.03). Five-year hard event-free survival increased from 6% to 26% from the highest to the lowest HRR quartile: see figure. Survival curve Conclusion A blunted HRR is a useful non-imaging predictor of adverse events during high dose dipyridamole-SE. It is additive over resting or inducible regional wall motion abnormalities, and unmasks a prognostically meaningful autonomic unbalance. Chronotropic incompetence during dipyridamole SE is a negative prognostic finding, equally important than RWMA.

Thrombotic microangiopathy as a cause of cardiovascular toxicity from the BCR-ABL1 tyrosine kinase inhibitor ponatinib

AbstractThe third-generation tyrosine kinase inhibitor (TKI) ponatinib has been associated with high rates of acute ischemic events. The pathophysiology responsible for these events is unknown. We hypothesized that ponatinib produces an endothelial angiopathy involving excessive endothelial-associated von Willebrand factor (VWF) and secondary platelet adhesion. In wild-type mice and ApoE−/− mice on a Western diet, ultrasound molecular imaging of the thoracic aorta for VWF A1-domain and glycoprotein-Ibα was performed to quantify endothelial-associated VWF and platelet adhesion. After treatment of wild-type mice for 7 days, aortic molecular signal for endothelial-associated VWF and platelet adhesion were five- to sixfold higher in ponatinib vs sham therapy (P < .001), whereas dasatinib had no effect. In ApoE−/− mice, aortic VWF and platelet signals were two- to fourfold higher for ponatinib-treated compared with sham-treated mice (P < .05) and were significantly higher than in treated wild-type mice (P < .05). Platelet and VWF signals in ponatinib-treated mice were significantly reduced by N-acetylcysteine and completely eliminated by recombinant ADAMTS13. Ponatinib produced segmental left ventricular wall motion abnormalities in 33% of wild-type and 45% of ApoE−/− mice and corresponding patchy perfusion defects, yet coronary arteries were normal on angiography. Instead, a global microvascular angiopathy was detected by immunohistochemistry and by intravital microscopy observation of platelet aggregates and nets associated with endothelial cells and leukocytes. Our findings reveal a new form of vascular toxicity for the TKI ponatinib that involves VWF-mediated platelet adhesion and a secondary microvascular angiopathy that produces ischemic wall motion abnormalities. These processes can be mitigated by interventions known to reduce VWF multimer size.

Multimodality Imaging in the Assessment of the Physiological Significance of Myocardial Bridging.

In myocardial bridging (MB) a segment of the coronary artery is covered by the myocardium. MB can be seen as a systolic compression by invasive coronary angiography (ICA) or as an intramural course by computed tomography angiography (CTA). Intramural course is a common incidental finding in CTA studies. Only minority of the bridging segments are associated with systolic compression causing a possible impairment of myocardial perfusion. The relationship between myocardial blood flow and MB is complex and poorly evaluated by anatomic imaging. Furthermore, provocation tests are frequently needed to uncover systolic compression. Fractional flow reserve can be used to assess the hemodynamic significance of MB. Nuclear perfusion imaging can demonstrate flow abnormalities associated with MB. Stress echocardiography can demonstrate ischemic wall motion abnormalities. They can be complemented by hybrid imaging with CTA to distinguish epicardial coronary artery disease and MB. This article will review different imaging modalities for the evaluation of the physiologic significance of MB.

Prognostic Value of Stress Echocardiography in Patients With Low-Intermediate or High Short-Term (10 Years) Versus Low (

This study evaluates the prognostic value of stress echocardiography (Secho) in short-term (10 years) and lifetime atherosclerotic cardiovascular disease risk-defined groups according to the American College of Cardiology/American Heart Association 2013 cardiovascular risk calculator. The ideal risk assessment and management of patients with low-to-intermediate or high short-term versus low (<39%) or high (≥39%) lifetime CV risk is unclear. The purpose of this study was to evaluate the prognostic value of Secho in short-term and lifetime CV risk-defined groups. We evaluated 4,566 patients (60 ± 13years; 46% men) who underwent Secho (41% treadmill and 59% dobutamine) with low-intermediate short-term (<20%) risk divided into low (<39%, n= 368) or high (≥39%, n= 661) lifetime CV risk and third group with high short-term risk (≥20%, n= 3,537). Follow-up (3.2 ± 1.5years) for nonfatal myocardial infarction (n= 102) and cardiac death (n= 140) were obtained. By univariate analysis, age (p <0.001) and ≥3 new ischemic wall motion abnormalities (WMAs, p<0.001) were significant predictors of cardiac events. Cumulative survival in patients was significantly worse in patients with ≥3 WMA versus <3 WMA in low-intermediate short-term and low (3.3% vs 0.3% per year, p <0.001) or high (2.0% vs 0% per year, p <0.001) lifetime risk and also in those with high short-term CV risk group (3.5% vs 1.0% per year, p <0.001). Multivariate Cox proportional hazards analysis identified ≥3 new ischemic WMAs as the strongest predictor of cardiac events (hazard ratio 3.0, 95% confidence interval 2.3 to 3.9, p<0.001). In conclusion, Secho results (absence or presence of ≥3 new ischemic segments) can further refine risk assessment in patients with low-intermediate or high short-term versus low or high lifetime cardiovascular risk. Event rate with normal Secho is low (≤1% per year) but higher in patients with high short-term CV risk by the American College of Cardiology/American Heart Association 2013 cardiovascular risk calculator.

Abstract 9440: Prognostic Value of Stress Echocardiography in Patients With Low (&lt;10%)-Intermediate (10-20%) Framingham Risk Score (Short-Term) versus Low (&lt;39%) or High (≥39%) Lifetime Predicted Risk of Cardiovascular Disease

Background: The ideal risk assessment and management of patients with low-intermediate or high Framingham risk score (FRS, short-term) versus low or high lifetime cardiovascular (CV) risk is unclear. The purpose of this study was to evaluate the prognostic value of stress echocardiography (SE) in defined FRS and lifetime risk groups. Methods: We evaluated 4566 patients (60±13 years; 46% male) undergoing SE (41% treadmill, 59% dobutamine) with low-intermediate FRS (&lt;20%) divided into: low (&lt;39%, n=368) or high lifetime (≥39%, n=661) CV risk and third group with high FRS (≥20%, n=3537). Follow-up (3.2±1.5 years) for non-fatal myocardial infarction (n=102) and cardiac death (n=140) were obtained. Results: By univariate analysis, age (p&lt;0.001), ejection fraction (p&lt;0.001) and ≥3 ischemic wall motion abnormalities (WMA) (p&lt;0.001) were significant predictors of cardiac events. Cumulative survival in patients with low or intermediate short term risk groups were significantly worse in patients with ≥3 WMA vs. &lt;3 WMA in low-intermediate FRS and low (3.3%/year vs. 0.3%/year, p&lt;0.001) or high lifetime CV risk (2.0%/year vs. 0%/year, p&lt;0.001) and high FRS group (3.5%/year vs. 1.0%/year, p&lt;0.001). Multivariate Cox proportional hazards analysis identified ≥3 new ischemic wall motion abnormalities as the strongest predictor of cardiac events (HR 3.2, 95% CI 2.2-4.6, p &lt;0.001). Conclusion: Stress echocardiography results (absence or presence of ≥3 ischemic segments) can equally and effectively risk stratify low-intermediate or high FRS versus low or high lifetime cardiovascular risk patients. Event rate with normal SE is highest in patients with high FRS.

Abstract 9333: Prognostic Value of Stress Echocardiography In Patients Achieving a High Exercise Workload (=10 Metabolic Equivalents) and Submaximal Heart Rate Response

Background: High exercise capacity (≥10 metabolic equivalents, METS) is a predictor of favorable prognosis. Submaximal studies (&lt;85% maximum predicted heart rate, MPHR) may lead to non-diagnostic results and indeterminate outcomes. The purpose of this study was to examine the prognostic value of stress echocardiography (SEcho) in patients achieving high exercise capacity and submaximal heart rate response. Methods: We evaluated 81 patients (50 ± 13 years; 62% male) achieving nine minutes (≥10 METS) and &lt;85% MPHR with treadmill SEcho. Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal SEcho was defined as stress-induced ischemia (wall-motion score of ≥1 grade). Followup (3.4 ± 1.5 years) for non-fatal myocardial infarction and cardiac death (n = 2) were obtained. Results: By univariate analysis, the number of new ischemic wall motion abnormalities (hazard ratio = 2.5, confidence interval 1.2 - 5.3, p = 0.02) was the most significant predictor of cardiac events. Cumulative survival in patients achieving nine minutes (≥10 METS) and &lt;85% MPHR was significantly worse in patients with abnormal (ischemic) vs. normal (nonischemic) SEcho (1.1%/year vs. 0.2%/year, p = 0.02)[Graph]. Conclusions: The ability to achieve nine minutes (≥10 METS), despite &lt;85% MPHR by treadmill SEcho was associated with a benign prognosis (~1.0%/year). In the setting of high achieved exercise capacity and &lt;85% MPHR, SEcho results (presence or absence of ischemia) were further able to sub-stratify this low risk group.

Abstract 9509: Prognostic Value of Treadmill Stress Echocardiography at Extremes of Exercise Workload: Submaximal, &lt;85% Maximum Predicted Heart Rate and High Exercise Capacity, ≥10 Metabolic Equivalents

Background: Submaximal stress testing, &lt;85% maximum predicted heart rate (MPHR) may be non diagnostic and high exercise capacity (≥10 metabolic equivalents, METS) is a predictor of favorable prognosis. The purpose of this study was to evaluate the prognostic value of submaximal and high exercise capacity stress echocardiography (EXSE). Methods: We evaluated 1781 patients (55 ± 13 years; 59% male) undergoing EXSE divided into 811 with submaximal (&lt;85% MPHR) and 970 with high exercise capacity (≥10 METS). Resting left ventricular ejection fraction and wall motion was assessed. The left ventricle was divided into 16 segments and scored on a 5-point scale of wall motion. Abnormal EXSE was defined as stress-induced ischemia (wall-motion score of ≥1 grade). Follow-up (3.3 ± 1.5 years) for non-fatal myocardial infarction (n = 40) and cardiac death (n = 52) were obtained. Results: By univariate analysis, exercise work load (p&lt;0.0001), ejection fraction (p&lt;0.0001) and number of new ischemic wall motion abnormalities (p&lt;0.0001) were significant predictors of cardiac events. Cumulative survival was significantly worse in patients with abnormal vs. normal EXSE in submaximal (4.5%/year vs. 1.4%/year, p&lt;0.0001) and high exercise capacity groups (1.1%/year vs. 0.2%/year, p=0.001) (Graph). Multivariate logistic regression analysis identified number of new ischemic wall motion abnormalities as the best predictor of cardiac events (p&lt;0.05) in both groups. Conclusions: Despite normal EXSE, inability to achieve 85% MPHR conferred a higher, intermediate event rate of 3.0%/year. The ability to achieve nine minutes (≥10 METS) on EXSE conferred a benign prognosis (1.0%/year) regardless of EXSE results. In either group (submaximal or high exercise capacity), EXSE results (absence or presence ischemia) were useful in further, effectively risk stratifying patients.

Abstract 8885: Prognostic Significance of Dyspnea versus Chest Pain in Patients Referred for Stress Echocardiography

Background: Stress echo (SEcho) is an established modality for diagnosis and risk stratification of patients with known or suspected coronary artery disease. The purpose of this study was to examine the prognostic significance of dyspnea versus chest pain in patients referred for SEcho. Methods: We evaluated 1335 patients (63 ± 13 years; 40% male) undergoing SEcho (49% treadmill, 51% dobutamine). Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal SEcho was defined as stress-induced ischemia (wall-motion score of ≥1 grade). Followup (3.5 ± 1.5 years) for non-fatal myocardial infarction (n = 42) and cardiac death (n = 39) were obtained. Results: By univariate analysis, both number of new ischemic wall motion abnormalities (p&lt;0.0001) and ejection fraction (p&lt;0.0001) were significant predictors of cardiac events. Cumulative survival was signficantly worse in patients with dyspnea vs. chest pain (2.3%/year vs. 1.4%/year, p=0.02). SEcho was further able to risk stratify normal (n = 289) vs. abnormal (n = 155) groups for dyspnea (1.0%/year vs. 4.4%/year; p &lt; 0.001), and normal (n = 608) vs. abnormal (n = 283) groups for chest pain (0.8%/year vs. 2.9%/year; p &lt; 0.001)(Figure). Multivariate logistic regression analysis identified number of new ischemic wall motion abnormalities as the strongest predictor of cardiac events (RR 1.7, 95% CI 1.0-2.9, p&lt;0.05). Conclusions: In patients referred for stress echocardiography, self-reported dyspnea identified a group of patients at increased risk for cardiac events. Stress echocardiography results (normal or abnormal) was further able to risk stratify both dyspnea and chest pain subgroups. Assessment of dyspnea should be incorporated into routine clinical evaluation of patients referred for stress echocardiography.

Abstract 9888: Is There Additional Prognostic Value of Stress Echocardiography in Patients Achieving a High Exercise Capacity (≥10 Metabolic Equivalents)?

Background: High exercise capacity is a predictor of favorable prognosis in patients with known or suspected coronary artery disease. The purpose of this study was to examine the prognostic value of stress echocardiography (SEcho) in patients achieving high exercise workload. Methods: We evaluated 970 patients (51 ± 11 years; 62% male) achieving nine minutes (≥10 metabolic equivalents) on a Bruce protocol by treadmill SEcho. Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal SEcho was defined as stress-induced ischemia (wall-motion score of ≥1 grade). Followup (3.4 ± 1.5 years) for non-fatal myocardial infarction (n = 11) and cardiac death (n = 3) were obtained. Results: By univariate analysis, both peak wall motion score index (p=0.002) and number of new ischemic wall motion abnormalities (p&lt;0.0001) were significant predictors of cardiac events. Cumulative survival in patients achieving nine minutes (≥10 metabolic equivalents) was signficantly worse in patients with abnormal (ischemic) vs. normal (nonischemic) SEcho (1.1%/year vs. 0.2%/year, p=0.001)(Graph). Multivariate logistic regression analysis identified number of new ischemic wall motion abnormalities as the strongest predictor of cardiac events (RR 1.27, 95% CI 1.0-1.6, p=0.01). Conclusions: The ability to achieve nine minutes (≥10 metabolic equivalents) by treadmill stress echocardiography confers a benign prognosis (~1.0%/year). In the setting of high achieved exercise capacity, stress echocardiography (absence or presence of ischemia) is further able to effectively risk stratify a low risk group.

Thoracoabdominal aortic aneurysm repair in high risk cardiac patients: A modified grafting technique

Severe cardiac disease is a major risk for early death following thoracoabdominal aortic aneurysm (TAAA) repair. Proximal aortic cross-clamping during TAAA repair dramatically increases left ventricular afterload risking myocardial ischemia. Although preoperative myocardial revascularization helps protect myocardium at risk during these periods of hemodynamic stress, in some patients myocardial revascularization is not feasible. Similarly, intraoperative shunting or bypass is not always practical. Under these circumstances we employ a modified multigraft technique during TAAA repair to reduce the risk of early death in high-risk cardiac patients. Case #1 is a 59-year-old male with end-stage ischemic cardiomyopathy (ejection fraction 15%), and recurrent admission for CHF, diagnosed with a 6 cm type III TAAA during evaluation for cardiac transplantation. Because of the potential need for intraaortic balloon support, he was not accepted for transplantation unless the TAAA could be repaired first. He underwent successful modified TAAA repair and subsequently had a successful cardiac transplant. He remains alive and well 3 years after TAAA repair. Patient #2 is a 70-year-old male who presented with an 8 cm type III TAAA. Cardiac evaluation revealed a history of prior myocardial infarction, severe nonreconstructable three-vessel coronary artery disease and inducible angina, left ventricular aneurysm, and ischemic wall motion abnormalities during dobutamine stress echocardiogram. Aneurysm size and multiple episodes of radiating central abdominal and back pain suspicious for aneurysm expansion precluded delays inherent to myocardial revascularization. He remains alive and well 10 months following successful modified TAAA repair. Patients with severe cardiac disease are at risk for early death following TAAA repair. Aortic cross-clamping contributes to this risk. The modified, multigraft technique of TAAA repair avoids aortic cross-clamping, minimizes myocardial risk, and may reduce early death.

Stress Echocardiography: Quantification and Identification of Ischaemic Wall Motion Through Speckle-tracking

Stress Echocardiography: Quantification and Identification of Ischaemic Wall Motion Through Speckle-tracking

Left Ventricular Diastolic Filling Pressures During Dobutamine Stress Echocardiography: Relationship to Symptoms and Ischemia

Limited information exists regarding the relationship of left ventricular diastolic filling parameters measured by Doppler echocardiography during dobutamine stress echocardiography (DSE) and stress-induced symptoms or myocardial ischemia. To determine if there is an association between Doppler parameters of left ventricular filling and symptoms and ischemic wall motion abnormalities during DSE, the authors prospectively studied 219 patients (mean age, 66+/-11 years; 55% men) referred for clinically indicated DSE. Pulsed-wave Doppler measurements of mitral inflow and medial annular tissue velocities at baseline, 20 microg/kg/min, peak stress, and recovery were made. Patients were classified as having stress-induced ischemia (n=70) or no ischemia (n=149) on the basis of the development of new or worsening wall motion abnormalities. Patients who developed ischemia had lower baseline and peak stress diastolic annular tissue velocities (e') (5.7+/-1.9 vs 6.4+/-1.9 cm/s at baseline, P=0.02; 5.2+/-1.6 vs 7.4+/-2.4 cm/s at peak stress, P<.0001). At peak stress, the E/e' ratio was higher (13.1+/-6.3 vs 10.2+/-4.2, P=.003); these differences persisted into recovery. The increase in E/e' from 20 microg/kg/min to peak stress was greater (0.9+/ 2.1 vs -0.8+/-3.1, P=.0009) in patients who developed symptoms during DSE and in patients who presented with dyspnea (0.3+/-2.6 vs -1.0+/-3.2, P=.02). The change in e' velocity from baseline to peak stress, the change in E/e' from baseline to recovery, known coronary artery disease, and the development of symptoms during DSE were independently associated with ischemia. The development of symptoms and myocardial ischemia during DSE are both associated with an increase in E/e'. The prognostic implications of elevated E/e' during DSE have yet to be elucidated.

Pharmacological stress: a useful exercise?

Over the past years cardiovascular magnetic resonance (CMR) imaging has been increasingly used to detect the presence of coronary artery disease and to assess its functional consequences to the myocardium [1]. Several approaches have been applied to detect coronary artery disease with CMR including direct visualization of coronary arteries and bypass grafts [2– 4] (magnetic resonance coronary angiography), the characterization of myocardial tissue [5–8] (delayed contrast enhancement) or the visualization of the effects of induced ischemia [9–17] (wall motion analysis or perfusion measurements). The latter is particularly valuable in clinical decision making since the detection of epicardial coronary luminal narrowing alone does not necessarily predict its hemodynamic consequences to the underlying myocardium. In the last decades, pharmacological stress has been extensively evaluated as an alternative stress method and is particularly advised to those patients who are not able to perform adequately either due to limited exercise capability or a disabling disease. With the development of rapid gradient systems and the routine application of advanced CMR scanner systems, it has become possible to perform cine imaging of the heart at rest and under stress conditions with CMR. Since space is limited within the MR scanner bore and patient movement impairs image quality, pharmacological stress is preferred for CMR imaging. Research efforts have been focused on the definition of the clinical role of magnetic resonance pharmacological stress for the detection of inducible wall motion abnormalities, preferably using dobutamine stress magnetic resonance (DSMR) [18–30]. High-dose DSMR proved to be highly accurate for the detection of inducible wall motion abnormalities and its usefulness for determination of patient prognosis has been shown [18–24]. DSMR at low-dose dobutamine levels was found to be highly predictive of functional improvement of resting wall motion abnormalities after coronary revascularization procedures (detection of viable myocardium) [25–27]. For induction of ischemic wall motion abnormalities, adenosine/dipyridamole or dobutamine are routinely used and the outcome is often considered alike and interchangeable. In a landmark study by Paetsch et al. [31], the results of a direct comparison of dobutamine stress CMR, adenosine stress CMR and adenosine stress CMR perfusion as assessed during a single, combined examination with all stress tests were evaluated against coronary angiography as the standard of reference. This study proved that dobutamine was superior to adenosine stress for the detection of inducible wall motion abnormalities related to the presence of epicardial coronary Editorial comment to the paper of Karamitsos et al. (doi: 10.1007/s10554-008-9392-3).

Direct Renin Inhibition

The process of cardiac healing and recovery after an acute myocardial infarction encompasses profound changes in the necrotic area (“infarct zone”), in the neighboring ischemic zone (“area at risk”), and in the nonischemic myocardium (“nonischemic region”). Patient’s prognosis ultimately depends on the functional, biochemical, electric, and structural changes taking place in these 3 different areas as a consequence of the acute ischemic event. These extracellular, cellular, and subcellular events are globally referred to as “postinfarction remodeling,” and therapeutic interventions able to slow or reverse its progression have a favorable impact on patient prognosis.1 A pivotal role in these processes is played by the renin-angiotensin-aldosterone system (RAAS) that is undoubtedly hyperactivated after myocardial infarction, together with other neural and endocrine systems. Locally synthesized angiotensin II has been suggested to act as an autocrine, paracrine, and intracrine modulator of cardiac function.2 Notably, the major components of the RAAS components have been shown in cardiac tissue, and extracardiac renin uptake is associated with local release by myocardial mast cells.3 Angiotensin II intracellular signal transduction involves the phosphorylation of several proteins, such as membrane transporters and selective ion channels, structural and contractile proteins, and enzymes that regulate metabolism, protein synthesis, and gene expression. These multiple actions are mediated via complex intracellular signaling pathways, including stimulation of the phospholipase C-inositol 1,4,5-trisphosphate-1,2-diacylglycerol cascade, mitogen-activated protein kinases, tyrosine kinases, RhoA/Rho kinase, and reactive oxygen species generation through vascular NADPH oxidase activation. Beyond directly affecting vasomotor tone, angiotensin II potentiates the effects of several vasoconstrictor hormones, facilitates the central and …

223 Heart frequency at which cardiac index starts its descending limb can identify ischemic wall motion abnormalities

223 Heart frequency at which cardiac index starts its descending limb can identify ischemic wall motion abnormalities

Dipyridamole/aspirin combination in secondary stroke prevention: effects on absolute myocardial blood flow and coronary vascular resistance

In the European Stroke Prevention Study (ESPS 2), oral administration of a fixed combination of 200 mg extended-release dipyridamole and 25 mg aspirin (twice daily) after ischemic stroke or transient ischemic attack, significantly reduced the risk of stroke compared to placebo as well as compared to aspirin or dipyridamole alone. However, the i.v. application of dipyridamole over 4 - 6 min is known to increase myocardial blood flow up to 6-fold, and thereby potentially provoke ischemic wall motion abnormalities in patients with coronary artery disease. We therefore assessed the cardiac side effects of the dipyridamole/aspirin combination on absolute myocardial blood flow (MBF) and coronary vascular resistance (CVR). MBF and CVR were measured using 150-water positron emission tomography in 24 patients after stroke or transient ischemic attack, before and 6.7 +/- 1.9 days after starting the dipyridamole/aspirin combination (Aggrenox) therapy. Resting MBF increased by 39% (max. 112%), from 0.92 +/- 0.13 (ml x g(-1) x min(-1)) at baseline to 1.28 +/- 0.27 (ml x g(-1) x min(-1)) under ongoing dipyridamole/aspirin combination therapy (p < 0.0005). CVR consecutively decreased from 105.3 +/- 16.9 to 74.1 +/- 16.5 (mmHg x ml(-1) x g x min) (p < 0.0005). The relative increase in MBF correlated negatively with the body surface area. No correlation was found between relative MBF increase and duration of dipyridamole/aspirin combination therapy (range 4 - 10 days). Orally administered dipyridamole/aspirin combination therapy in secondary stroke prevention increases MBF and decreases CVR significantly. These cardiac side effects of the dipyridamole/aspirin combination should be taken into account in stroke patients with proven or suspected coronary artery disease, particularly in combination with a small body surface area.