384 Morpho-functional analysis of subvalvular apparatus in mitral valve prolapse and response to dipyridamole stress echocardiography. A pilot study

Aims Myocardial fibrosis has been found in papillary muscles (PM) and basal segment of left ventricular (LV) inferior-lateral wall in patients with mitral valve prolapse (MVP), which may be due to stretch from valve. Moreover, ST-segment depression is common in patients with MVP, despite low prevalence of epicardial coronary artery disease, and it is attributed to microvascular dysfunction or myocardial stretch. Longitudinal strain (LS) correlates with myocardial fibrosis, while dipyridamole stress echocardiography (DSE) identifies microvascular dysfunction. We aimed at assessing morphology and function of PM and left ventricular walls at rest and during DSE by LS, and at determining prevalence of microvascular dysfunction in patients with MVP. Methods and results Seven consecutive patients with MVP (age 55.4 ± 15.7 years, 57% female) and LV ejection fraction 64 ± 5% underwent DSE. Length and LS of PM were measured at rest and retrospectively compared with those of patients with ischaemic heart disease (n = 8, age 67.1 ± 10.1 years, 37% female) and healthy controls (n = 8, age 39.6 ± 13.3 years, 50% female). LS of PM and LV was also determined at rest and during stress in MVP. Length of PM did not differ among groups, but in MVP, posterior PM was longer than the anterior PM (24 ± 3.8 vs. 20.6 ± 3.6 mm, P = 0.028). Significant difference in resting PM LS was found among groups (overall P = 0.04), with PM LS value in MVP (16.7 ± 7.1%) intermediate between ischaemic (14.2 ± 3.2%) and controls (20.5 ± 2.7%). No difference was found between rest and stress LS of PM in MVP. Global LS tended to increase in MVP during DSE compared to rest (23.1 ± 3.8% vs. 21.1 ± 2.6%, respectively, P = 0.07), while no significant difference between rest and stress LS was found in every LV myocardial segments. Nevertheless, in MVP, LS of LV inferior-lateral wall tended to improve under DSE in patients with mild regurgitation (19.7 ± 4.6 vs. 14.2 ± 5 at rest), but to decrease (16 ± 6.1 vs. 20.3 ± 2.3 at rest) in patients with severe mitral regurgitation (P = 0.006 for interaction). ST-segment depression was elicited by DSE in 29% of MVP. No significant difference in echocardiographic parameters was found between patients with and without ST-segment depression. Conclusions In MVP, sub-valvular apparatus may have peculiar morpho-functional features. DSE does not alter LS of PM, neither of LV walls, except for inferior-lateral wall, which impairs in severe mitral regurgitation. Prevalence of microvascular dysfunction is comparable to that of the general population.

Left ventricular contractile reserve, coronary flow reserve, and heart rate reserve during dipyridamole stress echocardiography predict survival in non-ischemic heart failure

Background Left ventricular contractile reserve (LVCR), coronary flow velocity reserve (CFVR), and heart rate reserve (HRR) have recognized independent impact on outcome in heart failure (HF). They all can be simultaneously measured during dipyridamole stress echocardiography (DSE). Aim To assess the value of comprehensive DSE in patients with non-ischemic heart failure. Methods We evaluated 613 patients with HF, no history of coronary artery disease and no inducible regional wall motion abnormalities: 270 patients with preserved (≥50%) ejection fraction; 147 with mid-range (40–49%) ejection fraction; 196 with HF and reduced (<40%) ejection fraction. All underwent DSE (0.84 mg/kg in 6') in 5 accredited laboratories. We measured LVCR (abnormal value ≤1.1), CFVR in left anterior descending artery (abnormal value ≤2.0), and HRR (peak/rest heart rate, abnormal value ≤1.22). All patients were followed-up. Results Abnormal CFVR, LVCR and HRR occurred in 29%, 44% and 46% of patients, respectively. After a median follow-up time of 20 months (interquartile range 12–32 months), 41 patients died. Annual mortality rate was lowest in patients (n=200) with normal response, and >10-fold higher in patients (n=96) with 3 abnormal criteria: see figure. At multivariable analysis, a reduced HRR (Hazard Ratio = 3.402, 95% Confidence Intervals 1.530–7.565, p=0.003) was the strongest SE independent predictor of all-cause death. Conclusion Abnormal LVCR, CFVR and HRR can be frequently observed during vasodilator SE in HF patients. They target different pathophysiological vulnerabilities (myocardial function, coronary microcirculation and cardiac autonomic system) and are useful for outcome prediction. FUNDunding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Consiglio nazionale delle ricerche - Institute of Clinical Physiology Figure 1

Pressure-Volume Relationship By Pharmacological Stress Cardiovascular Magnetic Resonance

Background. The variation between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an index of myocardial contractility, easily obtained during routine stress echocardiography and never tested during dipyridamole stress-cardiac magnetic resonance (CMR). We assessed the ΔESPVR index in patients with known/suspected coronary artery disease (CAD) who underwent dipyridamole stress-CMR.Methods. One-hundred consecutive patients (24 females, 63.76±10.17 years) were considered. ESPVR index was evaluated at rest and stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson’s method. Results. The ΔESPVR index showed a good inter-operator reproducibility. Mean ΔESPVR index was 0.48±1.45 mmHg/mL/m2. ΔESPVR index was significantly lower in males than in females. ΔESPVR index was not correlated to rest left ventricular end-diastolic volume index or ejection fraction. Forty-six of 85 patients had myocardial fibrosis detected by the late gadolinium enhancement technique and they showed significantly lower ΔESPVR values. An abnormal stress CMR was found in 25 patients and they showed significantly lower ΔESPVR values. During a mean follow-up of 56.34±30.04 months, 24 cardiovascular events occurred. At receiver-operating characteristic curve analysis, a ΔESPVR<0.02 mmHg/mL/m2 predicted the presence of future cardiac events with a sensitivity of 0.79 and a specificity of 0.68. Conclusions. The noninvasive assessment of the ΔESPVR index during a dipyridamole stress-CMR exam is feasible and reproducible. The ΔESPVR index was independent from rest LV dimensions and function and can be used for a comparative assessment of patients with different diseases. ΔESPVR by CMR can be a useful and simple marker for additional prognostic stratification.

The physiologic and prognostic value of regional longitudinal strain during dipyridamole stress echocardiography

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Investigaciones Médicas, Cardiodiagnostic Background. Regional apical longitudinal strain (RALS) allows to corroborate the diagnosis of regional wall motion abnormalities (RWMA) during dipyridamole stress echocardiography (DSE) on a quantitative basis but data on the prognostic value are missing. Objectives. The to evaluate the physiologic correlates and prognostic value of RALS vs. RWMA during DSE. Methods. In a single center, observational design we initially evaluated 150 patients (pts), mean age 68.3 ± 9.6 years, 50.7% men referred for DSE. RALS was defined as the average of the four apical segments from the 3 apical views. Any increase in the percentage of deformation was considered normal. Coronary flow velocity reserve (CFVR) was also assessed in mid-distal left anterior descending (LAD) coronary artery by pulsed-wave Doppler. Pts were divided into two groups (G). G1: patients with normal RALS, and G2: patients with abnormal RALS. Major cardiovascular event was considered to be: cardiovascular death, acute myocardial infraction (AMI), stroke or needs for revascularization after 3 months All patients were followed-up. Results. RALS success rate was 94.6% (142 pts), since 8 pts were excluded for inadequeate window. Eighty-seven patients (61.3%) were included in G1 and 55 (38.7%) pts in G2. The mean follow-up was 36 ± 0.93 months. There were no differences in the resting RALS between the G1 and G2 (-22.3% ± 3.3 vs -21.25% ± 4.9, p = NS), but significant differences in the peak dipyridamole effect (-26.3% ± 4.2 vs -18.8% ± 4.1, p &lt; 0.001). Pts G1 showed less RWMA than pts G2 (G1 3.4% vs G2 90 %), p &lt; 0.001) and higher CFVR (G1= 2.6 ± 0.5 vs G2 = 1.6 ± 0.4, p &lt; 0.001). Adequeate CFVR showed high concordance with the increase in RALS evaluated by Kappa Index 0.95, p 0.001 (Pts G1= 98.9% vs pts G2= 96.4%). In the long-term follow up, 24 pts experienced events: 3 deaths, 3 non-fatal myocardial infarctions, 2 stroke and 16 late revascularizations. Pts with normal RALS had a better event-free survival (G1= 90.8% vs G2 = 70.9%, log Rank p &lt; 0.007, HR: 2.92; 95% CI: 1.27-6.68, p 0.011) (figure 1). In the multivariate analysis of logistic regression, adjusted for age, the RALS was an independent predictor of event. In G2 no significant differences were detected in event free survival in pts with and without visual dyssynergies during DSE (73.7 vs 67.7, respectively (p = ns) Conclusions. A mismatch between RALS and visually assessed RWMA occurs in a significant proportion of patients, and RALS is better correlated to physiologic (CFVR) and prognostic standards. Abnormal RALS during DSE predicted worse outcome, regardless of the RWMA. Quantitative stress echocardiography is possible feasible and useful during DSE. Abstract Figure. RALS in DSE and Event Free Survival

The usefulness of dipyridamole stress echocardiography in high-risk patients before abdominal aneurism surgery

Funding Acknowledgements Type of funding sources: None. Background Coronary artery disease (CAD) and aortic aneurysm (AA) share commons risk factors, such as hypertension, diabetes mellitus, hypercholesterolemia, and smoking. Cardiac assessment before aortic abdominal aneurysm (AAA) surgery is indicated for patients with symptomatic coronary artery disease (CAD). The usefulness of assessment of moderate/high-risk patients is still debated. Purpose the purpose of our study is to evaluate the safety and effectiveness of dipyridamole stress echocardiography (DSE) for the detection of CAD in patients undergoing AAA surgery with high cardiovascular risk. Methods From 2017th to 2019th 120 patients underwent surgery for aortic aneurysm (71 endovascular technique and 49 with open laparotomy). Of these, 74 asymptomatic patients with high cardiovascular risk underwent a pre-surgical contrast-enhanced dipyridamole stress echo (0,84 mg/kg over 6 minutes – protocol with LVO with sulfur hexafluoride), to exclude the presence of inducible myocardial ischemia, Mean follow-up was 6-24 months. Results Mean age was 77 years +/- 6.6, with male gender prevalent (83%). No complication during DSE occurred; mean SCORE risk was 9.8% +/- 2.3%, with 63% patients with very high risk. Only 1 patient showed inducible ischemia during stress echocardiography, with evidence of significant LAD stenosis; no myocardial infarction was reported at follow-up, while 1 ischemic stroke and 1 unplanned revascularization occurred. 11% of patients died, of which 50% for Sars-Cov-2 disease and 12% due to post-surgery dissection while no cardiac deaths were found. Conclusions dipyridamole stress echo is safe in patients with surgical-class abdominal aortic aneurism; in patients with high cardiovascular risk but no symptoms reversible ischemia is rare. DSE should not be routinely performed before high-risk surgery but only in patients with cardiac symptoms. Abstract Figure. Patients Diagram

Abstract 12727: Microvascular Coronary Dysfunction Affects Global Longitudinal Strain After Dipyridamole Stress Echocardiography

Introduction: Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function. CMD can be identified, in patients with non-obstructive coronary artery disease (CAD), by a reduced transthoracic Doppler-derived coronary flow reserve (CFR), which is an index of coronary arterial reactivity. Hypothesis: The aim of this study was to investigate the dipyridamole-induced changes of global longitudinal strain (GLS) in patients with CMD. Methods: fiftythree patients (35M, 18F; mean age 67±8 years) without obstructive CAD, assessed by invasive coronary angiogram, underwent dipyridamole stress echocardiography. CFR were determined as the ratio of hyperaemic to baseline diastolic coronary flow velocity. CMD was defined as CFR < 2. GLS was visualized as a bull’s-eye map in a quick and feasible manner. In each patient, we used a frame rate of 70 frames/sec for adequate 2D strain analysis. We analyzed GLS at each step of stress test and compared peak-dose values with baseline. Results: Sixteen patients (30%) among the overall population showed CMD. There were no significant differences in baseline characteristics between patients with or without CMD. GLS, at baseline, was significantly lower in patients with CMD (-16.7±3.77 vs. -17.9±3.75 - p<0.01). We observed a different response to dipyridamole stress echocardiography, between the two groups: GLS significantly increased up to peak dose in patients without CMD (from -17.9±3.75 to -19.5±4.12 - p<0.01), whereas on the other hand, a significant decrease from rest to peak dose was observed in patients with CMD (from -16.7±3.77 to -15.4±4.21- p<0.01). There was a significant inverse correlation between CFR and delta GLS measured at rest and after dipyridamole peak dose (r = -0.83 - p<0.01). Conclusions: GLS analysis, performed by comparing dipyridamole peak-dose with baseline values, shows that in patients with CMD there is a different response of left ventricular myocardiim to stress test. It could be assumed that the inverse correlation between CFR and delta GLS reflects a progressive subclinical worsening of left ventricular myocardial function in these patients. Larger studies could confirm our data.

Inverse response of global longitudinal strain after dipyridamole stress echocardiography in patients with microvascular coronary dysfunction

Background Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function at rest and during stress. CMD can be identified, in patients with non-obstructive coronary artery disease (CAD), by a reduced transthoracic Doppler-derived coronary flow reserve (CFR), which is an index of coronary arterial reactivity, and can be impaired in both obstructive CAD and CMD. The aim of this study was to investigate the dipyridamole-induced changes of global longitudinal strain (GLS) in patients with CMD. Methods 43 patients (29M, 14F; mean age 68±7 years) without obstructive CAD, assessed by invasive coronary angiogram, underwent dipyridamole stress echocardiography. Coronary flow was assessed in the left anterior descending coronary artery (LAD) and was identified as the colour signal directed from the base to the apex of the left ventricle, containing the characteristic biphasic pulsed-Doppler flow signals. CFR were determined as the ratio of hyperaemic to baseline diastolic coronary flow velocity. CMD was defined as CFR &lt;2. GLS was measured using automated function imaging, through the positioning of three endocardial markers (two markers at the mitral annulus and one at the apex) in each apical view. Subsequently, the obtained segmental values of GLS were visualized as a bull's-eye map in a quick and feasible manner. We had optimal left ventricular endocardial tracking in the overall population. In each patient, we used a frame rate of 70 frames/sec for adequate 2D strain analysis. We analyzed GLS at each step of stress test and compared peak-dose values with baseline. Results Thirteen patients (30%) among the overall population showed CMD. There were no significant differences in baseline characteristics between patients with or without CMD. GLS, at baseline, was significantly lower in patients with CMD (−16.9±3.78 vs. −17.8±3.77 – p&lt;0.01). We observed a different response to dipyridamole stress echocardiography, between the two groups: GLS significantly increased up to peak dose in patients without CMD (from −17.8±3.77 to −19.3±4.09 – p&lt;0.01), whereas on the other hand, a significant decrease from rest to peak dose was observed in patients with CMD (from −16.9±3.78 to −15.5±4.18 – p&lt;0.01). There was a significant inverse correlation between CFR and delta GLS measured at rest and after dipyridamole peak dose (r=−0.82 – p&lt;0.01). Conclusions GLS analysis, particularly performed by comparing dipyridamole peak-dose with baseline values, shows that in patients with CMD there is a different response of left ventricular myocardiim to stress test. It could be assumed that the inverse correlation between CFR and delta GLS reflects a progressive subclinical worsening of left ventricular myocardial function in these patients. Larger studies could confirm our data. Funding Acknowledgement Type of funding source: None

Speckle-tracking during dipyridamole stress echocardiography in the detection of myocardial ischemia in patients with suspected coronary artery disease

Background The aim of this study was to investigate the incremental value of global longitudinal strain (GLS), postsystolic strain index (PSI) and prestretch (PSE) by automated function imaging with respect to wall motion (WM) and coronary flow reserve (CFR) for the diagnosis of significant coronary artery disease (CAD) during dipyridamole stress echocardiography. Methods We retrospectibely enrolled 227 patients with known or suspected CAD, approaching our echo lab to perform a DSE; all patient underwent coronary angiography within 1 month for clinical reasons. Obstructive CAD was defined as the evidence of &gt;70% stenosis during coronary angiogram. Obstructive CAD was detected in 143 (63%) patients, while 84 (37%) had no significant CAD. Global longitudinal strain, PSI and PSE were measured at rest and peak of the stress (after 6 minutes of 0,84mg/kg of dipyridamole infusion). Results Patient with CAD showed a significantly lower GLS at rest (−16.9±4.2 vs −18.6±3.4; p&lt;0.01) and peak (14.9±3.8 vs −21.50±3.3; p&lt;0.01) Figure A; the behavior of GLS was opposite, in patient with CAD showed an increase while in patient without CAD a significant decrease after dipyridamole infusion. There was also a significant difference between groups for Delta PSI (PSIpeak − PSIrest) and Delta PSE (PSEpeak − PSErest), respectively 126±145 vs −40±97, (p&lt;0.01) and 108±163 vs −41±106 (p&lt;0.01) Figure C. ROC analyses produced a statistically valid model: Average GLS at peak (p 0.001; AUC=0.906, cut-off value −18%, sensitivity 83% and specificity 82%); on the basis of these results, we compared WM and myocardial deformation analysis and GLS was superior to CFR LAD, Delta EF, Delta ESV and Delta WMI (Figure B). Conclusions GLS, PSE and PSI show an opposite response to dipyridamole, in patients with CAD in patient without CAD and show much higher sensitivity and specificity compared to the conventional parameters like WMI, EF and CFR in detecting CAD Funding Acknowledgement Type of funding source: None