Myocardial strain overrules left ventricular ejection fraction and late gadolinium enhancement extent in predicting MACE in CMR-proven acute myocarditis

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac magnetic resonance (CMR) plays a major role in both the diagnostic process and prognostic stratification in acute myocarditis. Presence of late gadolinium enhancement (LGE) and left ventricular (LV) ejection fraction (EF) are known predictors of major adverse cardiovascular events (MACE). However, in daily clinical practice it remains challenging to distinguish ‘the good from the bad’. The prognostic value of CMR feature tracking (FT) derived strain, with respect to LGE and LVEF, remains unclear.

Purpose

To evaluate the incremental prognostic value of left atrial (LA) phasic function, LV and right ventricular (RV) strain using CMR-FT in patients with CMR-proven acute myocarditis.

Methods

In this multicenter observational study, patients with CMR-proven acute myocarditis were included and followed with regard to MACE including all-cause mortality (ACM), heart-failure hospitalizations (HFH), and life-threatening arrhythmias (LTA). Using FT-derived strain, LV global longitudinal strain (GLS), circumferential strain (GCS), and radial strain (GRS), RV GLS and LA phasic function were measured. Uni- and multivariable analysis including clinical and CMR parameters were performed to assess the association with MACE.

Results

A total of 162 patients were included (75% male, 41 ±17 years). MACE occurred in 29 patients (18%, ACM n = 18, HFH n = 7, LTA n = 11) during a median follow-up of 5.5 (2.2-8.3) years. Forty-six percent had a STEMI-like presentation (combination of chest pain, elevated troponin, and ST-elevation, n = 74). LGE was present in 90% of patients and mean LVEF was 51 ± 12%. Patients with LVEF <50% had a significantly worse prognosis compared to patients with LVEF ≥50% (p < 0.0001, Figure A). When we categorized the study population into subgroups of quartile values of LV GLS, patients with LV GLS worse than 18% had a significant worse outcome compared to the other subgroups (p < 0.05, Figure B). Subgroups of LGE extent did not show significantly different associations with outcome (p = 0.458, Figure C). Cox regression analysis showed that LV strain and LA phasic function were univariably associated with MACE, whereas RV GLS and LGE extent were not. All univariable associated strain parameters were separately included in a multivariable model, including age, sex, STEMI-like presentation, and LVEF. LV GLS (HR 1.08, p = 0.01), LV GCS (HR 1.15, p = 0.02), and LV GRS (HR 0.98, p = 0.02) were independent predictors of MACE.

Conclusions

LV strain parameters are independent and incremental predictors of prognosis in patients with acute myocarditis, while RV strain and LA phasic function are not. Therefore, LV strain is a promising novel parameter for risk stratification in acute myocarditis.

Cardiovascular magnetic resonance for early detection of late cardiotoxicity in asymptomatic survivors of hodgkin and non-hodgkin lymphoma

Funding Acknowledgements

Type of funding sources: None.

Background

Long-term survivors of Hodgkin (HL) and non-Hodgkin (NHL) lymphomas experience late adverse effects of mediastinal radiotherapy and/or anthracycline containing chemotherapy, which lead to premature cardiovascular morbidity and mortality. It is unknown whether early stages of myocardial dysfunction and heart failure in these survivors can be detected by cardiovascular magnetic resonance imaging (CMR).

Purpose

To identify early sensitive markers for the detection of subclinical late cardiotoxicity using CMR in asymptomatic survivors of HL and (primary mediastinal large B-cell lymphoma) NHL.

Methods

For this prospective observational study, we included 80 HL or selected NHL survivors, who have been free of disease for ≥5 years and were treated with mediastinal radiotherapy (RT) with/without chemotherapy. Patients with known cardiac disease were excluded. Included patients were compared to 40 age- and sex matched healthy controls. CMR included 1) cine imaging for assessment of left ventricular (LV) and right ventricular (RV) dimensions, systolic function and strain; 2) 2-dimensional late gadolinium enhancement (LGE) imaging; 3) T2 mapping and 4) pre- and post-contrast T1 mapping (MOLLI) for assessment of native T1 values and extracellular volume (ECV).

Results

Of the 80 patients, 78 (98%) had a history of HL and 2 (2%) of NHL with a mean age of 47 ± 11 years (46% male). All patients were treated with mediastinal RT which was combined with anthracycline containing chemotherapy in 68 (85%) patients. The median interval between diagnosis and CMR was 20 [14 – 26] years. Differences in CMR characteristics between patients and healthy controls are shown in the table. LV end-systolic volume was statistically significantly higher, but LV ejection fraction and mass were significantly lower in patients compared to healthy controls. RV volumes were significantly lower in patients, but RV ejection fraction was preserved. Strain parameters of the LV, i.e. global longitudinal strain, global circumferential strain and global radial strain, were slightly but significantly reduced in patients. No significant differences were found in myocardial T2 times and ECV; however, native myocardial T1 time was significantly higher in patients compared to healthy controls. LGE was detected in 25% of the patients and in the majority of patients with LGE this was classified as hinge point fibrosis.

Conclusion

Asymptomatic survivors of HL and NHL are not exempt of late cardiotoxicity, which can be detected by subtle changes in LV myocardial function, strain and native T1 value with CMR. Furthermore, late gadolinium enhancement was present in 25% of the patients. Further longitudinal studies are needed to assess the implication of these changes in relation to clinical outcome.

Incremental value of cardiovascular magnetic resonance imaging in family screening for hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Genetic testing in relatives of hypertrophic cardiomyopathy (HCM) patients can lead to early identification of carriers of pathogenic DNA variants (G+), before onset of left ventricular hypertrophy (LVH). Repeated evaluation by electrocardiography (ECG) and transthoracic echocardiography (TTE) is recommended to detect HCM during follow-up. Cardiovascular magnetic resonance (CMR) imaging has become valuable in the work-up of HCM, although its role in G+ subjects has not been extensively evaluated. In this study, we investigated the value of CMR in the G+/LVH- population.

We included 55 G+ subjects who underwent CMR in addition to ECG and TTE, with a maximal wall thickness (MWT) <15mm on TTE. The CMR imaging protocol consisted at least of steady state free procession imaging and 2-dimensional late gadolinium enhancement (LGE) images. ECGs were considered abnormal in case of pathologic Q waves, T wave inversion or signs of LVH (by voltage criteria including Sokolow-Lyon and a Romhilt-Estes score ≥4). TTEs were abnormal in case of LVH (defined as MWT≥10mm). For both modalities, the diagnosis of HCM was based on a MWT≥13mm. The yield of CMR relative to ECG/TTE was assessed by comparing the proportion of HCM diagnoses and the presence of other phenotypic features. Forward step logistic regression was used to assess whether the presence of TTE/ECG abnormalities could predict reclassifications or abnormalities (crypts and LGE) on CMR.

An overview of ECG/TTE and CMR findings is shown in the Figure. Two of 16 (13%) subjects diagnosed with HCM on TTE were reclassified as having no HCM on CMR, and 8 of 39 (21%) subjects without HCM on TTE were reclassified as HCM on CMR. These 8 subjects had a mean MWT of 15.4 ± 2.6 mm on CMR and a mean MWT difference of 4.5 ± 2.9 mm (range 1.7-9.4) compared to TTE, which in 3 cases was explained by a hook-shaped thickening of the basal anterior wall in the 2 chamber view, not visible on TTE. Compared to subjects without HCM on both modalities, the reclassified group had a significantly higher QRS duration (104 ± 14 vs 93 ± 11 ms, p = 0.03) and anterior mitral valve leaflet length (30 ± 4 vs 26 ± 3 mm, p = 0.01). Of the 13 subjects with normal ECG/TTE results, none were reclassified as HCM using CMR.

The proportion of additional CMR abnormalities was large in subjects with and without abnormal ECG/TTE results (57% vs 38%, p = 0.24). Subjects with poor TTE image quality were equally likely to be reclassified compared to those with sufficient image quality (10% vs 24%, p = 0.19). Logistic regression demonstrated that the presence of TTE/ECG abnormalities (odds ratio [OR] 8.7 [1.3-59.0], p = 0.03) and age (OR 1.1 [1.0-1.2], p < 0.01) independently predicted reclassifications or presence of abnormalities using CMR.

Additional CMR imaging reclassifies 18% of subjects. Subjects with normal ECG and TTE results are not diagnosed as HCM on CMR, but the prevalence of HCM-related abnormalities on CMR was high in subjects with and without ECG/TTE abnormalities.

Abstract Figure. Diagnostic approach and CMR findings

Differences in left ventricular mass and morphology and right ventricular function differentiate phenotype-negative sarcomere gene mutation carriers from healthy volunteers

Funding Acknowledgements

Type of funding sources: None.

Carriers of pathogenic DNA variants (G+) causing hypertrophic cardiomyopathy (HCM) can be identified by genetic testing, before manifestation of left ventricular hypertrophy (LVH). These G+/LVH- subjects are routinely monitored for phenotypic expression, which, alongside LVH, can include other HCM-related abnormalities, including crypts and myocardial fibrosis. Cardiovascular magnetic resonance (CMR) imaging has emerged as a valuable technique in diagnosing and follow-up of HCM. In this study, we identified clinical features of subclinical HCM in a G+/LVH- population compared to healthy subjects.

We studied 33 G+ subjects with CMR and a maximal wall thickness (MWT) <13mm, and compared them to an age- and gender-matched group of 35 healthy controls  (44 ± 14 vs 48 ± 10 y, p = 0.17; 11 (33%) vs 12 (34%) men, p = 0.93). The CMR imaging protocol consisted of 1) steady state free procession cine imaging, 2) 2-dimensional late gadolinium enhancement (LGE) images in the G+ patients and 3) pre-contrast T1 mapping using a modified look-locker inverse recovery sequence. We assessed CMR examinations for features of HCM. Forward logistic regression analysis was performed to determine which of the CMR characteristics were predictive of G+ status.

G+ subjects had a higher MWT (10.9 ± 1.6 vs 10.2 ± 1.3 mm, p = 0.04), a similar interventricular septal wall (IVS) thickness (8.8 ± 1.6 vs 8.7 ± 1.6 mm, p = 0.85), a smaller posterior wall (PW) and a higher IVS/PW ratio (6.6 ± 1.2 vs 7.7 ± 1.3mm, p < 0.001; 1.4 ± 0.3 vs 1.1 ± 0.2, p = 0.001). Indexed left ventricular (LV) mass was significantly lower in the G+ group (Table). LV function was similar (63 ± 6 vs. 61 ± 5%, p = 0.12), but right ventricular (RV) function was higher in the G+ group. They often had a characteristic hook-shaped thickening of the basal anterior wall (7 (21%) vs 0, p < 0.004; Figure) and  more frequently exhibited myocardial crypts. Midwall LGE was present in 3 (9%) G+ subjects. Native septal T1 values were elevated in G+ patients compared to controls, although mostly within the normal range (986 ± 31 vs 963 ± 28 ms, p < 0.01). Crypts, indexed LV mass and RV ejection fraction were significant predictors of G+ status in logistic regression analysis (Table).

CMR demonstrates significant morphological differences between the G+/LVH- population and healthy controls. Further studies are needed to assess the prognostic significance of these morphological features.

Predictors of genotype-positive status Variables G+ subjects (n = 33) Controls (n = 35) P value OR for G+ status P value Left ventricular mass/BSA (g/m²) 45 ± 7.4 53 ± 7.9 <0.001 0.86 [0.78-0.95] 0.003 Right ventricular ejection fraction (%) 58 ± 6 53 ± 4 <0.001 1.15 [1.00-1.32] 0.047 Crypts 17 (55%) 4 (11%) <0.001 9.62 [1.93-48.00] 0.006 G+: genotype-positive, OR: odds ratio Abstract Figure. CMR findings

Cardiac sarcoidosis: frequency, diagnostic approach and follow-up in a tertiary center

Background

Cardiac sarcoidosis (CS) is associated with poor prognosis, making early diagnosis and treatment important. The aim of this study is to evaluate our diagnostic results and follow-up for the diagnosis of CS in a tertiary center.

Methods

We studied 188 patients with proven extra-cardiac sarcoidosis referred to our outpatient clinic for evaluation of cardiac involvement. Eight patients were excluded because electrocardiogram (ECG) and/or transthoracic echocardiography (TTE) was missing. Cardiac magnetic resonance (CMR) and/or positron emission tomography (PET) was performed in 66% and 37% of the patients, respectively. Median follow-up duration was 2.9 [1.2–5.3] years. The diagnosis of CS was based on the Heart Rhythm Society criteria.

Results

Cardiac symptoms defined as palpitations, angina, dyspnea and (near)-syncope were present in 156 of 180 (87%) patients. Any abnormality on ECG (bundle branch blocks, atrioventricular blocks, sinus tachycardia or atrial fibrillation) and/or TTE (left ventricular ejection fraction <55%, presence of regional wall abnormalities or myocardial hypertrophy) was found in 92/180 (51%) patients. CS was diagnosed in 42 of 180 (23%) patients, of whom 31 (74%) had any ECG and/or TTE abnormalities. However, ECG and/or TTE abnormalities were also present in 44% of the patients without cardiac involvement. Patients with CS showed a second type II or third degree AV-blocks in 3/42 (7%), a left ventricular ejection fraction <35% on TTE in 9/42 (21%), late gadolinium enhancement by CMR consistent with CS in 28/34 (82%), and myocardial FDG uptake by PET in 19/31 (61%). In 84 of the 138 patients without cardiac involvement, CMR was performed. In 15 patients an alternative diagnosis was found (i.e. myocardial infarction or other non-ischemic cardiomyopathy). The estimated 8-year cumulative event rate composite endpoint of sustained ventricular tachycardia, ventricular fibrillation, aborted sudden cardiac death, heart transplantation and all-cause mortality was 41% in the CS patients and 12% in the patients without CS (Figure 1, p<0.001).

Conclusions

In our study, 23% of the patients with proven extra-cardiac sarcoidosis was diagnosed with CS. Cardiac symptoms, ECG and TTE were of limited diagnostic value for screening for CS. CMR provided a good diagnostic yield and identified other cardiac diseases in a substantial number of patients.

Figure 1. KMCurve_CompositeEndpoint

Funding Acknowledgement

Type of funding source: None

P1825 Myocardial bridging and coronary artery disease in hypertrophic cardiomyopathy: a matched case control study

Funding Acknowledgements

None.

Introduction

The etiology of chest pain in hypertrophic cardiomyopathy (HCM) is diverse and includes coronary artery disease (CAD) as well as HCM-specific causes. Myocardial bridging (MB) has been associated with HCM, chest pain, and accelerated atherosclerosis. To investigate differences in the presence of MB and CAD, we compared HCM patients with age-, gender- and CAD pre-test probability (PTP)-matched outpatients presenting with chest pain.

Methods

We studied 84 HCM patients who underwent cardiac computed tomography and compared these with 168 matched controls (age 54 ± 11 years, 70% men, PTP 12% [5%–32%]). MB, calcium score, plaque morphology and presence and extent of CAD were assessed for each patient. Linear mixed models were used to assess differences between cases and controls.

Results

Differences between HCM patients and controls are described in the table. In summary, MB was more often seen in HCM patients (50% vs. 25%, p < 0.001), who were also more likely to have >1 segment affected (14% vs. 2%, p < 0.05). In the HCM group, MB was associated with pathogenic mutation status. Calcium score and the presence of obstructive CAD were similar in both groups (9 [0-225] vs. 4 [0-82] and 18% vs. 19%; p > 0.05 for both).

Conclusion

MB was twice as prevalent in the HCM group. However, in a matched analysis, the prevalence and extent of CAD was equal among patients with and without HCM. These finding illustrate that despite a higher prevalence of MB, the prevalence of CAD is similar between groups, also demonstrating satisfactory performance of pre-test risk prediction in HCM patients.

Assessment of CAD by CT HCM group(n = 84) Control group (n = 168) p-value Agatston score 9 [0-225] 4 [0-82] 0.22 No. of pts with score* 0.07 0-399 31 (89%) 149 (91%) >400 8 (11%) 15 (9%) Obstructive CAD 15 (18%) 32 (19%) 0.82 No. of pts with MB 42 (50%) 42 (25%) <0.001 No. of vessels with MB <0.001 1 34 (40%) 39 (23%) 2 8 (10%) 3 (2%) No. of pts with >1 segment with MB 12 (14%) 4 (2%) <0.001 Abbreviations CAD = Coronary artery disease, MB = Myocardial bridging, pts = patients *Only measured in 73/84 HCM patients and in 164/168 control patients

P5280The impact of background phase offset errors in cardiovascular magnetic resonance phase contrast imaging: a multi-scanner study

Background

Phase contrast (PC) CMR flow measurements (FM) are widely used for blood flow assessment, but they suffer from phase offset errors (POE). Stationary phantom correction limits these inaccuracies, however, this adds scan time. Stationary tissue (ST) correction is an alternative method that does not require additional scanning. The aim of this study was to evaluate the impact of POE, to assess interscanner variation, and to evaluate the ST correction usage.

Methods

We included 166 patients in which both aorta and main pulmonary artery FM were acquired including static gelatin phantom data. Subjects were scanned on three types of 1.5T scanners from the one vendor. Uncorrected and ST corrected FM were compared with phantom corrected FM, our reference value, and corrected for BSA. A difference of >10% in net flow was defined as clinically relevant. Regurgitation fraction was calculated and POE influences were assessed. Regurgitation severity was graded and POE influence on severity grading was assessed.

Results

Of the 166 cases included, the median age was 27 (5–74) years. Overall, the median difference between no corrected and phantom corrected FM was ≤6%, however, with a wide range of over- and underestimation (−155%–78% change) (figure). ST correction resulted in larger differences compared to no correction (p<0.01). Clinically significant differences were seen in 19% of all FM with no correction and in 30% of with ST correction (p<0.01). Furthermore, there were significant differences between scanners (no correction 10%, p<0.01; ST correction, p<0.01). Regurgitation severity indexing changed in 38 (11%) cases with no correction and in 48 (48%) with ST correction.

Magnitude of flow change with and without offset corrections (n=332) Flow (ml/m2) Δ no correction and phantom correction (%) Δ ST correction and phantom correction (%) Clinically significant difference (>10%) Mean ± SD Median IQR Range Median IQR Range No correction, N (%) ST correction , N (%) MRI 1 (n=126) 50±12 3 0 to 6 −8 to 30 5 −3 to 9 −26 to 28 13 (10%) 34 (27%) MRI 2 (n=102) 48±13 −2 −15 to 6 −155 to 78 5 −3 to 11 −74 to 52 50 (49%) 50 (49%) MRI 3 (n=104) 48±12 −1 −1 to 0 −7 to 14 2 −2 to 5 −39 to 29 1 (1%) 16 (15%) Total (n=332) 49±12 0 −2 to 4 −155 to 78 3 −2 to 8 −74 to 52 64 (19%) 100 (30%)

Conclusion

Background POE have a significant impact on flow quantification and regurgitation severity. Unexpectedly, background correction using ST correction worsens accuracy compared to no correction. POE vary greatly between scanners. Therefore, careful assessment of FM at each scanner is essential to determine if routine phantom scanning is necessary.

Orthostatic hypotension in older persons: a diagnostic algorithm

Orthostatic hypotension (OH) is a frequent phenomenon in older persons and usually has a multifactorial origin. When the diagnosis is suspected, the work-up should initially be directed at the most prevalent causes. This clinical algorithm may be a useful tool in the diagnostic process.