Duration of adenosine-induced myocardial hyperemia - Insights from quantitative 13N-ammonia positron emission tomography myocardial perfusion imaging

AIMS

To assess the impact of adenosine on quantitative myocardial blood flow (MBF) in a rapid stress-rest protocol compared to a rest-stress protocol using 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) and to gain insights into the time dependency of such effects.

METHODS AND RESULTS

Quantitative MBF at rest (rMBF), during adenosine-induced stress (sMBF) and myocardial flow reserve (MFR) were obtained from 331 retrospectively identified patients who underwent 13N-ammonia PET-MPI for suspected chronic coronary syndrome and who all exhibited no perfusion defects. Of these, 146 (44.1%) underwent a rapid stress-rest protocol with a time interval (Δtstress-rest) of 20 ± 4 minutes between adenosine infusion offset and rest-imaging, as per clinical routine. The remaining 185 (55.9%) patients underwent a rest-stress protocol and served as the reference. Groups did not differ regarding demographics, risk factors, medication, left ventricular function, and calcium scores. rMBF was significantly higher in the stress-rest vs. the rest-stress group (0.80 [IQR 0.66-1.00] vs. 0.70 [0.58-0.83] ml·min-1·g-1, p < 0.001) and, as sMBF was identical between groups (2.52 [2.20-2.96] vs. 2.50 [1.96-3.11], p = 0.347), MFR was significantly lower in the stress-rest group (3.07 [2.43-3.88] vs. 3.50 [2.63-4.10], p < 0.001). There was a weak correlation between Δtstress-rest and rMBF (r = -0.259, p = 0.002) and between Δtstress-rest and MFR (r = 0.163, p = 0.049), and the proportion of patients with abnormally high rMBF was significantly decreasing with increasing Δtstress-rest.

CONCLUSIONS

Intravenously applied adenosine induces a long-lasting hyperemic effect on the myocardium. Consequently, rapid stress-rest protocols could lead to an overestimation of rMBF and an underestimation of MFR.

Reproducibility of Left Ventricular Function Derived From Cardiac Magnetic Resonance and Gated 13N-Ammonia Positron Emission Tomography Myocardial Perfusion Imaging: A Head-to-Head Comparison Using Hybrid Positron Emission Tomography/Magnetic Resonance

RATIONALE AND OBJECTIVES

Cardiac magnetic resonance (CMR) and gated 13N-ammonia positron emission tomography myocardial perfusion imaging (PET-MPI) offer accurate and highly comparable global left ventricular ejection fraction (LVEF) measurements. In addition to accuracy, however, reproducibility is crucial to avoid variations in LVEF assessment potentially negatively impacting treatment decisions. We performed a head-to-head comparison of the reproducibility of LVEF measurements derived from simultaneously acquired CMR and PET-MPI using different state-of-the-art commercially available software.

MATERIALS AND METHODS

93 patients undergoing hybrid PET/MR were retrospectively included. LVEF was derived from CMR and PET-MPI at two separate core labs, using two state-of-the-art software packages for CMR (cvi42 and Medis Suite MR) and PET (QPET and CardIQ Physio). Intra- and inter-reader agreement was assessed using correlation and Bland-Altman (BA) analyses.

RESULTS

While intra- and inter-reader reproducibility of LVEF was high among both modalities and all software packages (r ≥ 0.87 and ICC≥0.91, all significant at p < 0.0001), LVEF derived from PET-MPI and analyzed with QPET outperformed all other analyses (intra-reader reproducibility: r = 0.99, ICC=0.99; inter-reader reproducibility: r = 0.98, ICC=1.00; Pearson correlations significantly higher than all others at p ≤ 0.0001). BA analyses showed smaller biases for LVEF derived from PET-MPI (-0.1% and +0.9% for intra-reader, -0.4% and -0.8% for inter-reader agreement) than those derived from CMR (+0.7% and +2.8% for intra-reader, -0.9% and -2.2% for inter-reader agreement) with similar results for BA limits of agreement.

CONCLUSION

Gated 13N-ammonia PET-MPI provides equivalent reproducibility of LVEF compared to CMR. It may offer a valid alternative to CMR for patients requiring LV functional assessment.

Tissue Doppler echocardiography and outcome in arrhythmogenic right ventricular cardiomyopathy

AIMS

This study aimed at investigating whether tissue Doppler imaging (TDI) is associated with adverse events in arrhythmogenic right ventricular cardiomyopathy (ARVC).

METHODS AND RESULTS

Transthoracic echocardiography was performed in 72 patients with definite (n = 63) or borderline (n = 9) ARVC diagnosed according to the 2010 Task Force Criteria and included in the prospective Zurich ARVC registry. Myocardial peak systolic tissue velocity (S') was measured by TDI at lateral tricuspid (tricuspid S'), medial mitral (septal S'), and lateral mitral annulus (lateral S'). Association of echocardiographic parameters with outcome was assessed by univariable Cox regression. During a median follow-up of 4.9 ± 2.6 years, 6 (8.3%) patients died of cardiovascular cause or received heart transplantation and 21 (29.2%) patients developed sustained ventricular arrhythmia. Tricuspid, septal, and lateral S' were lower in patients who died (p = 0.001; p < 0.001; p = 0.008; respectively), while tricuspid and septal S' were lower in those with ventricular arrhythmia (p = 0.001; p = 0.008; respectively). There was a significant association of tricuspid, septal, and lateral S' with mortality (HR = 1.61, p = 0.011; HR = 2.15, p = 0.007; HR = 1.67, p = 0.017; respectively), while tricuspid and septal S' were associated with ventricular arrhythmia (HR = 1.20, p = 0.022; HR = 1.37, p = 0.004; respectively). Kaplan-Meier analyses demonstrated a higher freedom from mortality with tricuspid S' >8 cm/s (p = 0.001) and from ventricular arrhythmia with S' >10.5 cm/s (p = 0.021).

CONCLUSIONS

This study demonstrates that TDI provides information on the ARVC phenotype, is associated with adverse events in ARVC patients, and differentiates between patients with and without adverse events.

Heart failure in COVID-19: the multicentre, multinational PCHF-COVICAV registry

Aims

We assessed the outcome of hospitalized coronavirus disease 2019 (COVID‐19) patients with heart failure (HF) compared with patients with other cardiovascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia). We further wanted to determine the incidence of HF events and its consequences in these patient populations.

Methods and results

International retrospective Postgraduate Course in Heart Failure registry for patients hospitalized with COVID‐19 and CArdioVascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia) was performed in 28 centres from 15 countries (PCHF‐COVICAV). The primary endpoint was in‐hospital mortality. Of 1974 patients hospitalized with COVID‐19, 1282 had cardiovascular disease and/or risk factors (median age: 72 [interquartile range: 62–81] years, 58% male), with HF being present in 256 [20%] patients. Overall in‐hospital mortality was 25% (n = 323/1282 deaths). In‐hospital mortality was higher in patients with a history of HF (36%, n = 92) compared with non‐HF patients (23%, n = 231, odds ratio [OR] 1.93 [95% confidence interval: 1.44–2.59], P < 0.001). After adjusting, HF remained associated with in‐hospital mortality (OR 1.45 [95% confidence interval: 1.01–2.06], P = 0.041). Importantly, 186 of 1282 [15%] patients had an acute HF event during hospitalization (76 [40%] with de novo HF), which was associated with higher in‐hospital mortality (89 [48%] vs. 220 [23%]) than in patients without HF event (OR 3.10 [2.24–4.29], P < 0.001).

Conclusions

Hospitalized COVID‐19 patients with HF are at increased risk for in‐hospital death. In‐hospital worsening of HF or acute HF de novo are common and associated with a further increase in in‐hospital mortality.

Left ventricular mechanics and cardiovascular outcomes in non-compaction phenotype

AIMS

This study aims at understanding left ventricular (LV) mechanics of non-compaction (LVNC) phenotype using echocardiographic strain analysis and at assessing the association of functional parameters with cardiovascular (CV) outcomes.

METHODS AND RESULTS

Longitudinal (GLS) and circumferential strain (GCS) as well as rotation of the LV were analyzed in 55 LVNC patients and 55 matched controls. Cardiovascular outcomes were documented for a median follow-up duration of 6 years. GLS and GCS were impaired in LVNC. Similary, regional longitudinal and circumferential strain as well as twist were reduced. CV events occurred in 28 LVNC patients. Apical peak circumferential strain (APCS), peak systolic rotation of apical segments (APSR), and twist were strongly associated with events. This was independent of and incremental to LVEF and non-compacted to compacted myocardial thickness ratio (NC:C ratio). The association of twist with events was also independent of and slightly superior to GLS.

CONCLUSIONS

GLS, GCS, regional strain, and twist were impaired in LVNC. APCS, APSR, and twist exhibited strong association with CV events independent of and incremental to LVEF and NC:C ratio, and in case of twist even GLS. Thus, STE-derived parameters may complement the echocardiographic assessment of LVNC patients in clinical routine.

P3689Association of echocardiographic progression and genetic profile in arrhythmogenic right ventricular cardiomyopathy

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is frequently associated with mutations in genes coding for desmosomal proteins. In this study, we investigated the association of genetic status with ARVC progression as defined by echocardiographic parameters.

Methods

We tested 62 ARVC patients for their genetic profile. Accordingly, they were grouped in mutation positive (48 (77%) patients; median age 48.5 years; 33 (69%) males), and mutation negative (14 (23%) patients; median age 45 years; 10 (71%) males). Prevalent mutations were Desmoglein-2 (DSG2) in 16 (26%), Desmoplakin (DSP) in 14 (23%), and Plakophilin-2 (PKP2) in 9 (15%) patients.

Results

At baseline, there were no significant differences in clinical characteristics between the two groups. Patients were followed-up for a median time period of 1420 days, and there was no significant difference in the duration of follow-up between the two groups (p=0.05).

In the mutation positive group, there was a significant increase in right ventricular end-diastolic area (p=0.002), right atrial short (p=0.008) and long (p=0.002) diameter, left atrial diameter (p=0.014), and a decrease in left ventricular ejection fraction (p=0.014) during follow up. Right ventricular functial parameters did not change significantly (tricuspid annular plane systolic excursion: p=0.24; fractional area change: p=0.088).

In the mutation negative group, none of the aforementioned echocardiographic findings exhibited any significant difference during follow-up: right ventricular end-diastolic area (p=0.1); right atrial short (p=0.7) and long (p=0.9) diameter, left atrial diameter (p=0.6), and left ventricular ejection fraction (p=0.3). Similarly, right ventricular functional parameters did not change significantly (tricuspid annular plane systolic excursion: p=0.77; fractional area change: p=0.80. Results are summarized in the figure.

Change in echocardiographic findings.

Conclusions

There is a strong association between echocardiographic progression of ARVC phenotype and the presence of a pathogenic mutation. Such mutations should be searched in all patients with an ARVC phenotype, and mutation positive individuals should be followed-up in shorter intervals.

[Therapeutic Strategies in Patients with Stable Coronary Artery Disease: The Role of Coronary Revascularization]

Therapeutic Strategies in Patients with Stable Coronary Artery Disease: The Role of Coronary Revascularization Abstract. Coronary artery disease is the leading cause of death worldwide. Prevention and optimal treatment of patients with coronary artery disease is therefore crucial. Lifestyle changes, optimal medical therapy and aggressive risk factor control represent key elements in the management of patients with stable coronary artery disease. Coronary revascularization of flow-limiting coronary artery stenoses is indicated to reduce myocardial ischemia and related symptoms. This review summarizes treatment strategies of patients with stable coronary artery disease, focusing on the 2018 European Society of Cardiology (ESC) guidelines of myocardial revascularization.