Prognostic utility of left ventricular global longitudinal strain in patients with systemic amyloidosis

Background

Myocardial deposition of amyloid proteins results in restrictive cardiomyopathy. Left ventricular global longitudinal strain (GLS) has emerged as a sensitive measure for detecting subclinical cardiac dysfunction over traditional echocardiographic parameters. However, multiple studies have provided differing conclusions regarding prognostic utility of impaired GLS in patients with systemic amyloidosis.

Purpose

We conducted a systematic review and meta-analysis to evaluate whether impaired GLS was associated with increased mortality or major adverse cardiovascular events (MACE) in patients with systemic amyloidosis.

Methods

We performed a literature search of Embase, Medline and Web of Science databases to identify studies that reported the association of GLS with clinical outcomes in patients with systemic amyloidosis (light chain or TTR amyloidosis). Outcomes of interest included all-cause mortality and MACE, defined as a composite of death or heart transplant or heart failure hospitalization. Unadjusted and adjusted hazard ratio (uHR and aHR respectively) were pooled using a random effects model. Heterogeneity among the studies was assessed using the Higgins I2 value.

Results

Out of 2139 initial citations, 28 observational studies with a total of 2713 patients were included in the analysis. The mean age ranged between 58–78 years and 62% of the patients were male. Most patients had cardiac amyloidosis (83%) and light-chain amyloidosis accounted for 69% of cases. Mean follow-up ranged between 1 and 5 years. GLS was significantly higher (less negative) (mean difference (MD) −3.69 [−5.94, −1.44], I2=87, p<0.01) in non-survivors compared with survivors. Similarly, patients who experienced MACE had a significantly higher mean GLS (MD −3.22, [−5.21, −1.22,], I2=82, p<0.01]. The risk of both mortality and MACE increased significantly for every −1% increase in GLS. In unadjusted models, a GLS above the defined threshold value was associated with a significantly higher risk of mortality (uHR: 1.66 [1.22, 5.21], I2=85.2, p<0.01) and MACE (uHR: 2.24 [1.28, 3.92], I2=39, p<0.01). In multivariable models an increase in GLS by −1% was an independent predictor of mortality (aHR: 1.09 [1.01,1.16], I2=53, p=0.02) and MACE (aHR: 1.24 [1.14,1.36], I2=0, p<0.01).

Conclusion

In patient with amyloidosis, the baseline left ventricular GLS may help identify patients with a higher risk of mortality and MACE.

Funding Acknowledgement

Type of funding sources: None.

Diastolic stress echocardiography in patients with normal resting diastolic function: prognostic utility in presence and absence of myocardial ischemia

Background

Abnormal diastolic response to exercise is reportedly associated with worse cardiovascular events. However, this has not been well studied in patients with normal diastolic function at rest.

Purpose

We sought to study diastolic response to exercise in patients referred for exercise stress echocardiography (ExE) and to explore its association with adverse outcomes in the presence and absence of exercise-induced myocardial ischemia.

Methods

In a retrospective study, patients referred for ExE to assess myocardial ischemia between April 2017 and December 2018 were enrolled. Patients were included if they had guideline-defined normal diastolic function at rest and availability of a full set of post exercise diastolic variables (post exercise tissue Doppler derived septal mitral annular early diastolic velocity (e'), ratio of pulsed Doppler derived mitral forward flow early diastolic velocity (E) over e' (E/e') and continuous wave Doppler derived maximum tricuspid regurgitation velocity (TRV)). The patients were followed for a median of 3.4 years for the occurrence of composite death, acute coronary syndrome, cardiac hospitalization, and need of follow-up ischemia testing. Abnormal exercise diastolic variables were defined as e' <7 cm/s, E/e' >15, and TRV >2.8 m/s.

Results

We studied 492 patients [age: 55.7±12.9 year, 268 (54%) women, EF: 61±5.8%]. Mean achieved metabolic equivalents of tasks (METs) was 9.7±3.1, and a total of 49 (10%) patients had evidence of exercise-induced ischemia. At rest, mean left atrial volume index was 25.4±12 ml, e' was 8±2 cm/s, E/e' was 9.5±2.4, and TRV was 2.1±0.44 m/s. Post exercise e' was 10±3 cm/s [<7cm/s in 63 (13%)], E/e' was 11.1±3.9 [>15 in 95 (19%)], and TRV was 2.37±0.68 m/s [>2.8 m/s in 152 (31%)]. Ischemic ExE was found to be strongly associated with the outcome (HR: 4.46, 95% CI: 2.8 to 7.1, p<0.001). In addition, all diastolic variables predicted the outcome in isolation if they were abnormal (e': 2.28, 95% CI: 1.4 to 3.7, p=0.001, E/e': 1.81; 95% CI: 1.15 to 2.84, p=0.01; TRV: 1.58, 95% CI: 1.17 to 2.13, p=0.003). When combined, however, association with the outcome was seen only when 2 or 3 of these variables were abnormal simultaneously (Figure 1A). When patients were stratified by ischemia and abnormal diastolic variables (figure 1B), patients with 2 or 3 abnormal variables were more likely to experience the outcome compared to patients with 0 or 1 abnormal variables in both absence of ischemia (p<0.001) and presence of ischemia (p=0.016). The stratified groups were different in their clinical and exercise profiles, with worse profiles in patients with both ischemia and 2 or 3 abnormal variables, and best profiles in patients with no ischemia and 0 or 1 abnormal variables.

Conclusions

In patients referred for ExE to assess ischemia with normal baseline diastolic function, exercise can unmask abnormal diastolic properties and stratify patients' risk regardless of the overt myocardial ischemia.

Funding Acknowledgement

Type of funding sources: None.

Prognostic role of positron emission tomography in patients with known or suspected cardiac sarcoidosis. a systematic review and meta-analysis

Background

Sarcoidosis is a chronic inflammatory disorder of unclear etiology, characterized by the presence of non-caseating granulomas. Cardiac involvement occurs in upto 27 percent of patients, manifesting as atrioventricular blocks, ventricular arrhythmia or sudden cardiac death. Current guidelines cite insufficient evidence for the prognostic utility of positron emission tomography (PET) in patients with cardiac sarcoidosis. Thus, we performed a systematic review and meta-analysis of published studies to ascertain the prognostic significance of PET imaging in patients with suspected or diagnosed cardiac sarcoidosis.

Purpose

To review current literature and determine if PET has prognostic utility in patients with known or suspected cardiac sarcoidosis

Methods

We performed a comprehensive literature search of electronic databases (Embase, Medline and Web of Science) using MeSH terms and keywords for sarcoidosis and PET from inception through December 2019. Studies were eligible if they included patients with known and/or suspected cardiac sarcoidosis undergoing evaluation by PET with or without perfusion imaging and reported clinical events of interest. An abnormal PET study was defined as the presence of focal or focal-on-diffuse uptake of 18- fluorodeoxyglucose (18-FDG) by visual analysis. In studies with perfusion imaging, patients with only perfusion defects were excluded. The primary outcome of interest was a composite of major adverse cardiac events (MACE), including sustained ventricular tachycardia, sudden cardiac death. Secondary analysis studied association of MACE with focal right ventricular (RV) uptake in patients with an abnormal PET study. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Heterogeneity of results among the studies was assessed using the Higgins I2 value.

Results

Out of a total of 1645 citations, 40 were selected for full-text review. Five studies were included in the final analysis with a total of 465 patients. mean follow-up was 2.3 years. Three of the five studies also reported frequency of abnormal RV uptake of 18-FDG. Patients with abnormal 18-FDG uptake on visual assessment had higher odds of MACE (OR 3.12, CI 1.9–5.01, p<0.00001), compared to known or suspected cardiac sarcoid patients with normal PET studies. Heterogeneity among studies was low (I2 = 0). In patients with an abnormal PET study, abnormal focal RV uptake of 18-FDG was associated with higher odds of MACE (OR 5.24, CI 1.1–25.1, p=0.04), with moderate heterogeneity among studies (I2=41).

Conclusion

In patients undergoing PET imaging for known or suspected cardiac sarcoidosis, abnormal metabolism on visual analysis is associated with increased risk of MACE. Furthermore, focal RV uptake further increases the risk of MACE in patients with abnormal PET imaging. Thus, PET imaging can serve as a tool to risk stratify patients with known or suspected cardiac sarcoidosis.

Forrest Plots

Funding Acknowledgement

Type of funding source: None

P3432Coronary artery calcium score is of limited sensitivity in detecting subclinical atherosclerosis in young individuals with family history of coronary artery disease

Introduction

Family history of premature coronary artery disease (CAD) is known to predispose individuals to adverse CAD events, often at a younger age. Current risk stratification strategy is suboptimal, as up to 50% of individuals were considered “low-risk” prior to their first presentation of myocardial infarction. Coronary artery calcium score (CACS) is a marker of atherosclerosis and provides incremental value in risk stratification. However, the utility of CACS may be limited in younger patients as they often have non-calcified atherosclerotic plaques. In this study, we evaluate the sensitivity of CACS in detecting subclinical atherosclerosis in different age groups.

Method

From 310 referrals to a specialized unit in the management of early atherosclerosis, 222 individuals with a family history of premature CAD (defined as CAD events in first-degree family members, male<55 and female<65) and aged between 35 and 55 were enrolled for assessment of their CAD risks. Individuals with possible, probably or definite familial hypercholesterolemia were excluded. In addition to clinical and risk factor evaluation, cardiac CT and CACS were performed in select individuals, at the discretion of the treating physician.

Results

Of the 141 (59% male, mean age 45.9±6.0 year) individuals that completed clinical evaluation, 65 (73% male, mean age 47.4±6.9 years) have subclinical atherosclerosis (defined by the presence of atherosclerotic plaques in any of the coronary artery segments in cardiac CT). Of them, 52 have CACS>0, giving an overall sensitivity of 80%. The breakdown by age group is shown in table 1. The sensitivity of CACS in detecting subclinical atherosclerosis is quite modest in younger individuals (60% in individuals <45 year-old) but improves with patient age (>85% in >45 years).

Table 1. Sensitivity of CACS in different age groups Age group True Positive Fast Negative Sensitivity N (CAC+ CTCA+) (CAC+ CTCA−) (%) <40 6 4 60 10 41–45 7 4 55 11 46–50 19 3 86 22 51–55 20 1 95 21

Conclusion

In younger individuals (<45 years) with family history of premature CAD, CACS is of limited sensitivity in detecting subclinical atherosclerosis, and should not be used to rule out CAD. Further studies are warranted.

P3412Risk factors, biomarkers and framingham risk estimate fail to identify presence of subclinical atherosclerosis in young individual with family history of premature coronary artery disease

Introduction

Patients with family history of premature coronary artery disease (CAD) are at increased risk of CAD events at a younger age. Risk factor based approaches and clinical evaluation are most commonly used to assess these individuals. However, it has been recently shown that up to 50% of individual presenting with their first myocardial infarction (MI) were considered to be “low risk” prior to that event. MI is often a result of plaque rupture preceded by progression of subclinical atherosclerosis. Detection of subclinical atherosclerosis may therefore help target prevention of plaque progression. We assessed the value of clinical risk factor, biomarkers and Framingham Risk Score (FRS) in predicting subclinical atherosclerosis in individuals with a family history of premature CAD.

Methods

From 310 referrals, 222 individuals between the ages of 35 and 55 with a family history of premature CAD (CAD events in first-degree family members (male <55, female <65)) were enrolled for evaluation of risk of CAD. Those with familial hypercholesteremia (possible, probable or definite) were excluded. Patients underwent clinical and risk factor evaluations as well as Cardiac CT or Calcium Score (CS) to assess presence of subclinical / clinical atherosclerosis at the discretion of the treating physician.

Results

In this pilot, 141 individuals (59% male, mean age 45.9±6.0 years) completed evaluation, and 65 (46%) had evidence of subclinical atherosclerosis on CT coronary angiography or CT calcium score with a mean segment involvement score (SIS) of 2.8 and mean CS of 152, putting them above the 80th percentile for their age and sex. Aside from male sex, age, and smoking history, other traditional risk factors and biomarkers including diabetes mellitus, hypertension, total cholesterol, LDL-C, HDL-C and Cholesterol/HDL-C were not significantly different between those with or without subclinical atherosclerosis (Table 1).

Table 1

Conclusion

In young individuals with a family history of premature CAD, risk factors, biomarkers, and FRS failed to identify individuals with premature, subclinical atherosclerosis in this pilot study. Detection of subclinical atherosclerosis and early implementation of treatment with the aim of stabilizing plaques and stopping progression might prove vital in reducing events in these individuals. Further studies are warranted.