Prognostic value of exercise stress echocardiography in patients with known coronary artery disease

Funding Acknowledgements

Type of funding sources: None.

Background

Exercise stress echocardiography (EE) is useful for diagnosis and risk stratification in patients (pts) with suspected coronary artery disease (CAD). Pts with known CAD carry a high risk of events. Our aim was to assess the utility of EE in predicting outcomes in this population.

Methods

Single center retrospective study of consecutive pts with known CAD who performed an EE between 2018 and 2019. The primary endpoint was a composite of admission for acute coronary syndrome (ACS), coronary revascularization and cardiovascular death during the follow-up.

Results

A total of 76 pts were included (mean age 59±9 years; 87% male). Fifty-nine (78%) pts had history of ACS, 51 (67%) of percutaneous coronary intervention (PCI) and 14 (18%) of coronary artery bypass graft. The majority of pts had 2 or more vessel disease (42 pts; 55%).

The main reason for performing EE was new onset of chest pain (38 pts; 50%) followed by functional assessment of coronary stenoses after incomplete revascularization (29 pts; 38%). The majority of pts had a preserved left ventricular ejection fraction (67; 88%). The exam was performed under beta-blocker effect in 35 (46%) pts.

The results of EE were positive for myocardial ischemia in 7 (9%) pts, negative in 37 (49%) pts and inconclusive in 32 (42%) pts. Mean exercise time was 8±3 minutes and mean METs achieved was 9.4±2.6. ST-segment depression fulfilling electrocardiographic criteria for ischemia occurred in 17 (22%) pts. Eleven (14%) pts complained of chest pain during the exam.

During a median follow up of 22 months (IQR 15-26), the primary endpoint occurred in 9 pts (admission for ACS in 5 pts; revascularization for chronic coronary syndrome in 4 pts). No cardiovascular death occurred. The positive predictive value of EE for the primary endpoint was 57.1% and the negative predictive value (NPV) 97.3%.

In a survival analysis, the predictors of the primary endpoint were lower exercise time, lower METs achieved, untreated significant coronary lesions and a positive EE (figure).

After adjustment in a multivariate analysis, a positive EE was an independent predictor of the primary endpoint (HR 4.6, 95%CI: 1.1-16.7, p=.044).

Conclusion

In pts with known CAD, EE had a high NPV and a positive result was an independent predictor of future cardiovascular events.

Impact of an inconclusive exercise stress echocardiogram on cardiovascular outcomes

Funding Acknowledgements

Type of funding sources: None.

Background

Exercise stress echocardiography (ESE) is used for the assessment of suspected or known coronary artery disease (CAD); however, a certain percentage of ESE studies are inconclusive. We aim to evaluate the prognostic impact of an inconclusive ESE on cardiovascular outcomes.

Methods

Single-center retrospective study of consecutive patients (pts) who performed an ESE between 2018 and 2019 for diagnosis or stratification of CAD. All pts performed a symptom-limited Bruce protocol. ESE was considered inconclusive when 85% of age-predicted maximum HR was not reached. Primary endpoint was a composite of admission for acute coronary syndrome (ACS), coronary revascularization and cardiovascular death during the follow-up.

Results

A total of 141 pts were included (76% male; mean age 60 ± 9 years). ESE was inconclusive in 51 (36%) pts, positive in 11 (8%) and negative in 79 (56%).

The mean exercise time of pts with inconclusive ESE was 7 ± 2 minutes and 76% had normal functional capacity. Fatigue (25 pts; 49%) and lower extremities pain (11 pts; 22%) were the main reasons for ESE stopping. Five pts (10%) complained of chest pain during exam.

Pts with an inconclusive ESE were more diabetic (inconclusive 43%, positive 9%, negative 13%; p=.001), had more chronic obstructive pulmonary disease (COPD) (14%, 0%, 2.5%; p=.026), performed more frequently the exam under beta blocker (BB) therapy (59%, 27%, 18%; p=.041) and had less ST-segment depression fulfilling electrocardiographic criteria for ischemia (10%, 64%, 27%, p<.001). Their functional capacity was worse than negative ESE pts (p<.001).

During a median follow up of 22 months (IQR 15-27), 13 (9.2%) pts had the primary endpoint, including 5 pts (3.5%) with ACS.

Pts with an inconclusive ESE had a lower incidence of the primary outcome than pts with a positive ESE and a higher incidence of events than pts with negative results (figure).

In multivariate analysis, after adjusting for functional capacity and electrocardiographic criteria for ischemia, an inconclusive ESE was an independent predictor of the primary endpoint (HR 9.7, IC95% 1.1-87,6 p= .042)

Conclusions

The frequency of inconclusive ESE is not negligible (36%). These pts had more diabetes and COPD and performed the exam under BB therapy more frequently, highlighting the importance of proper patient selection. An inconclusive ESE was associated to a higher risk of cardiovascular events compared to negative ESE. Abstract Figure.

Prevalence and clinical impact of latent obstruction in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by varying degrees of left ventricular outflow tract obstruction (LVOTobs). We aim to define the prevalence, clinical profile and impact of LVOTobs under physiological exercise in HCM patients (pts).

METHODS

Single center retrospective study of consecutive HCM pts without LVOTobs at rest (resting gradient <30mmHg), referred for exercise stress echocardiogram (ESE) between 2015 and 2019. Significative latent obstruction was defined as a LVOT gradient ≥50 mmHg during exercise or at early recuperation.

RESULTS

A total of 56 pts were included (64% men, mean age 57 ± 11 years, 61% septal HCM). The majority of pts (47; 84%) were in NYHA I functional class, 20 (36%) had history of syncope or pre-syncope (S/pS) and 7 (13%) had an implantable cardioverter defibrillator (ICD). Twelve (21%) pts had systolic anterior motion (SAM) of the mitral valve at rest.

Thirty-five (63%) pts performed ESE under beta-blocker (BB) therapy. Mean exercise time was 8 ± 3 min. During ESE, 2 (4%) pts developed a LVOT gradient between 30 to 50 mmHg and 17 pts (30%) developed a significative LVOTobs gradient (mean 85 ± 18 mmHg).

Pts with significative latent LVOTobs had more previous complaints of S/pS (59% vs 26%, p=.017), a tendency for a higher NYHA functional class (p=.082) and were more frequently on BB therapy (82% vs 18%, p=.043). Mean septum thickness was similar between groups (17 ± 0.7 vs 16 ± 0.6 mm, p=.536). The presence of SAM at rest was more frequent in the significative latent LVOTobs pts (p<.001). No differences were noted in exercise tolerance (p=.526).

During a median follow-up of 43 (IQR 15-53) months, 7 (41%) pts with significative latent LVOTobs had a pre-syncope, 3 (18%) were diagnosed with atrial fibrillation and 2 (12%) had a cardiovascular admission . There was up-titration/initiation of BB therapy in 5 (29%) pts, referral for septal myectomy in 3 (18%) and ICD implantation for primary prevention in 3 (18%) pts. No proper ICD shocks, sustained ventricular arrythmias or deaths occurred.

Comparing significative latent to non LVOTobs pts, the first ones had more ICD implantation (log rank p =.04) and performed a surgical myectomy more frequently (log rank p= .018) during the follow-up.

CONCLUSION

In our study, significative latent LVOTobs was observed in 30% of pts. Its presence can have clinical implications in HCM pts approach and should be suspected in more symptomatic pts and when SAM is present at rest.

How to distinguish between hypertrophic cardiomyopathy and left ventricular hypertrophy secondary to Fabry disease?

Introduction

Fabry disease (FD) commonly leads to left ventricular hypertrophy (LVH) that could mimic sarcomeric hypertrophic cardiomyopathy (HCM).

Purpose

To determine the differences in echocardiographic parameters between FD patients with LVH and HCM patients.

Methods

We conducted a prospective study encompassing FD patients followed in a Reference Center of Lysosomal Storage Disorders. All patients performed a complete echocardiographic evaluation, including left ventricular strain analysis by two-dimensional speckle tracking imaging. Demographic, clinical characteristics and echocardiographic parameters were analysed. FD patients with LVH were compared with HCM patients, using Chi-square test for categorical variables and Student's T-test for continuous variables. The significance level was 0,05.

Results

A total of 91 FD patients were included, with a median age of 51 years-old and 62,6% of female predominance. 16,5% of patients were under enzymatic replacement therapy with agalsidase alpha and 7,7% were treated with chaperone therapy (migalastat). 33 FD patients (36%) had LVH and were older than HCM patients (63,6 vs 59,3 years-old; p=0,106). FD patients with LVH had lower interventricular septum (IVS) thickness (16,4 vs 19,6 mm, p<0,001), IVS/posterior wall ratio (1,3 vs 1,8, p<0,001), and left atrial volume index (34,45 vs 42,2 ml/m2; p=0,014). Left ventricle mass index was similar between the two groups (157,7 vs 155,5 g/m2; p=0,819), with lower left ventricular ejection fraction in FD patients (64,5% vs 70,5%; p<0,001). There were no significant differences in global longitudinal strain (−15,6% vs 15,9%; p=0,687), global circumferential strain (−19,9% vs −21,1%; p=0,218) and global radial strain (35,3% vs 33,7%; p=0,623). Interestingly, FD patients had lower base-to-apex circumferential strain gradient (5,7% vs 9,1%; p=0,002) and lower twist (17,5° vs 26,1°; p=0,001) than HCM patients. No significant differences were reported regarding mechanical dispersion (72,4 vs 71,2 ms; p=0,841).

Conclusion

The pattern of LVH is different between FD and HCM patients. In our study, we revealed that base-to-apex circumferential strain gradient and twist are echocardiographic parameters that could help distinguish both entities.

Funding Acknowledgement

Type of funding sources: None.

Twist, left ventricular longitudinal and circumferential strain are early markers of cardiac involvement in Fabry disease

Introduction

Fabry disease (FD) is an X-linked progressive and multisystemic disease. Cardiac involvement is common and left ventricular hypertrophy (LVH) is the main cardiac manifestation.

Purpose

To determine the differences in echocardiographic parameters between FD patients without LVH and healthy controls.

Methods

We conducted a prospective study encompassing FD patients followed in a Reference Center of Lysosomal Storage Disorders. All patients performed a complete echocardiographic evaluation, including left ventricular strain analysis by two-dimensional speckle tracking imaging. Demographic, clinical characteristics and echocardiographic parameters were analysed. FD patients without LVH were compared with healthy controls, using Chi-square test for categorical variables and Student's T-test for continuous variables. The significance level was 0,05.

Results

A total of 91 FD patients were included, with a median age of 51 years-old and 62,6% of female predominance. 16,5% of patients were under enzymatic replacement therapy with agalsidase alpha and 7,7% were treated with chaperone therapy (migalastat). 58 patients (64%) did not present LVH. FD patients without LVH were younger (44,2 vs 52,9 years-old, p<0,001), had higher interventricular septum thickness (9,3 vs 8,4 mm, p=0,006) and left ventricular mass index (77,2 vs 68,4 g/m2, p=0,003) than healthy controls. Left ventricular ejection fraction was preserved in both groups (63,3% vs 65,4%; p=0,067). Global longitudinal strain (−19,6% vs −20,9%; p=0,003) and global circumferential strain (−17,9% vs −20,9%; p<0,001) were significantly lower in FD patients without LVH compared to healthy controls. Global radial strain was also lower, although without statistical significance (36,4% vs 41,4%, p=0,058). FD patients without LVH presented a lower base-to-apex circumferential strain gradient (5,7% vs 7,7%; p=0,035), but a higher base-to-apex longitudinal strain gradient (7,5% vs 4,3%; p<0,001), compared to controls. Left ventricular twist was also significantly lower in FD patients without LVH (13,8° vs 21,7°, p<0,001).

Conclusion

Left ventricular strain and twist analysis are useful to identify subclinical myocardial impairment in FD patients without LVH.

Funding Acknowledgement

Type of funding sources: None.