Regional contribution to ventricular stroke volume is affected on the left side, but not on the right in patients with pulmonary hypertension

Non-invasive imaging techniques for early diagnosis of bilateral cardiac dysfunction in pulmonary hypertension: current crests, future peaks

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease that eventually leads to heart failure (HF) and subsequent fatality if left untreated. Right ventricular (RV) function has proven prognostic values in patients with a variety of heart diseases including PAH. PAH is predominantly a right heart disease; however, given the nature of the continuous circulatory system and the presence of shared septum and pericardial constraints, the interdependence of the right and left ventricles is a factor that requires consideration. Accurate and timely assessment of ventricular function is very important in the management of patients with PAH for disease outcomes and prognosis. Non-invasive modalities such as cardiac magnetic resonance (CMR) and echocardiography (two-dimensional and three-dimensional), and nuclear medicine, positron emission tomography (PET) play a crucial role in the assessment of ventricular function and disease prognosis. Each modality has its own strengths and limitations, hence this review article sheds light on (i) ventricular dysfunction in patients with PAH and RV-LV interdependence in such patients, (ii) the strengths and limitations of all available modalities and parameters for the early assessment of ventricular function, as well as their prognostic value, and (iii) lastly, the challenges faced and the potential future advancement in these modalities for accurate and early diagnosis of ventricular function in PAH.

Myocardial strain parameters in pulmonary hypertension are determined by changes in volumetric function rather than by hemodynamic alterations

PURPOSE

To investigate associations of cardiac magnetic resonance feature-tracking-derived left (LV) and right ventricular (RV) global myocardial peak strains and strain rates with volumetric function and hemodynamic parameters to identify the major determinants of myocardial strain alterations in pulmonary hypertension (PH).

METHODS

Sixty-seven patients with PH or at risk of developing PH underwent right heart catheterization (RHC) and cine realtime imaging at 3 T. RHC parameters included mean pulmonary arterial pressure (mPAP), which was used for the diagnosis of PH. LV and RV volumetric function and feature-tracking-derived global radial, circumferential, and longitudinal (GLS) peak strains, together with their strain rates, were evaluated from cine images using routine software. Furthermore, myocardial strain parameters of 24 healthy subjects were evaluated as controls. Means were compared by t-test; relationships between parameters were investigated by correlation and regression analysis.

RESULTS

Compared to controls, RV-GLS, all RV systolic strain rates and the LV systolic longitudinal strain rate showed lower magnitudes in PH (RV-GLS: -21 ± 4% vs. -16 ± 5%, p < 0.0001); the strongest univariate correlate to mPAP was the RV-GLS (r = 0.59). All LV and RV strain parameters yielded stronger correlations with their respective ejection fractions. In bi-linear models using mPAP and ejection fraction as predictors, mPAP remained significant only for diastolic LV radial and circumferential strain rates.

CONCLUSION

Impairment of myocardial strains is more strongly associated with alterations in LV and RV volumetric function parameters than elevated mPAP, therefore limiting diagnostic information of myocardial strain parameters in PH.

Heart Failure Preserved Ejection Fraction in Women: Insights Learned from Imaging

While the prevalence of heart failure, in general, is similar in men and women, women experience a higher rate of HFpEF compared to HFrEF. Cardiovascular risk factors, parity, estrogen levels, cardiac physiology, and altered response to the immune system may be at the root of this difference. Studies have found that in response to increasing age and hypertension, women experience more concentric left ventricle remodeling, more ventricular and arterial stiffness, and less ventricular dilation compared to men, which predisposes women to developing more diastolic dysfunction. A multi-modality imaging approach is recommended to identify patients with HFpEF. Particularly, appreciation of sex-based differences as described in this review is important in optimizing the evaluation and care of women with HFpEF.

Increased biventricular hemodynamic forces in precapillary pulmonary hypertension

Precapillary pulmonary hypertension (PHprecap) is a condition with elevated pulmonary vascular pressure and resistance. Patients have a poor prognosis and understanding the underlying pathophysiological mechanisms is crucial to guide and improve treatment. Ventricular hemodynamic forces (HDF) are a potential early marker of cardiac dysfunction, which may improve evaluation of treatment effect. Therefore, we aimed to investigate if HDF differ in patients with PHprecap compared to healthy controls. Patients with PHprecap (n = 20) and age- and sex-matched healthy controls (n = 12) underwent cardiac magnetic resonance imaging including 4D flow. Biventricular HDF were computed in three spatial directions throughout the cardiac cycle using the Navier-Stokes equations. Biventricular HDF (N) indexed to stroke volume (l) were larger in patients than controls in all three directions. Data is presented as median N/l for patients vs controls. In the RV, systolic HDF diaphragm-outflow tract were 2.1 vs 1.4 (p = 0.003), and septum-free wall 0.64 vs 0.42 (p = 0.007). Diastolic RV HDF apex-base were 1.4 vs 0.87 (p < 0.0001), diaphragm-outflow tract 0.80 vs 0.47 (p = 0.005), and septum-free wall 0.60 vs 0.38 (p = 0.003). In the LV, systolic HDF apex-base were 2.1 vs 1.5 (p = 0.005), and lateral wall-septum 1.5 vs 1.2 (p = 0.02). Diastolic LV HDF apex-base were 1.6 vs 1.2 (p = 0.008), and inferior-anterior 0.46 vs 0.24 (p = 0.02). Hemodynamic force analysis conveys information of pathological cardiac pumping mechanisms complementary to more established volumetric and functional parameters in precapillary pulmonary hypertension. The right ventricle compensates for the increased afterload in part by augmenting transverse forces, and left ventricular hemodynamic abnormalities are mainly a result of underfilling rather than intrinsic ventricular dysfunction.

Atrioventricular plane displacement and regional function to predict outcome in pulmonary arterial hypertension

To investigate if left and right atrioventricular plane displacement (AVPD) or regional contributions to SV are prognostic for outcome in patients with pulmonary arterial hypertension (PAH). Seventy-one patients with PAH and 20 sex- and age-matched healthy controls underwent CMR. Myocardial borders and RV insertion points were defined at end diastole and end systole in cine short-axis stacks to compute biventricular volumes, lateral (SVlat%) and septal (SVsept%) contribution to stroke volume. Eight atrioventricular points were defined at end diastole and end systole in 2-, 3- and 4-chamber cine long-axis views for computation of AVPD and longitudinal contribution to stroke volume (SVlong%). Cut-off values for survival analysis were defined as two standard deviations above or below the mean of the controls. Outcome was defined as death or lung transplantation. Median follow-up time was 3.6 [IQR 3.7] years. Patients were 57 ± 19 years (65% women) and controls 58 ± 15 years (70% women). Biventricular AVPD, SVlong% and ejection fraction (EF) were lower and SVlat% was higher, while SVsept% was lower in PAH compared with controls. In PAH, transplantation-free survival was lower below cut-off for LV-AVPD (hazard ratio [HR] = 2.1, 95%CI 1.2-3.9, p = 0.02) and RV-AVPD (HR = 9.8, 95%CI 4.6-21.1, p = 0.005). In Cox regression analysis, lower LV-AVPD and RV-AVPD inferred lower transplantation-free survival (LV: HR = 1.16, p = 0.007; RV: HR = 1.11, p = 0.01; per mm decrease). LV-SVlong%, RV-SVlong%, LV-SVlat%, RV-SVlat%, SVsept% and LV- and RVEF did not affect outcome. Low left and right AVPD were associated with outcome in PAH, but regional contributions to stroke volume and EF were not.

Imaging in Women with Heart Failure: Sex-specific Characteristics and Current Challenges

Cardiovascular disease (CVD) represents a significant threat to women's health. Heart failure (HF) is one CVD that still has an increasing incidence and about half of all cases involve women. HF is characterised by strong sex-specific features in aetiology, clinical manifestation and outcomes. Women are more likely to have hypertensive heart disease and HF with preserved ejection fraction, they experience worse quality of life but have a better overall survival rate. Women's hearts also have unique morphological characteristics that should be considered during cardiovascular assessment. It is important to understand and highlight these sex-specific features to be able to provide a tailored diagnostic approach and therapeutic management. The aim of this article is to review these aspects together with the challenges and the unique characteristics of different imaging modalities used for the diagnosis and follow-up of women with HF.

The Interventricular Septum Is Biomechanically Distinct from the Ventricular Free Walls

The interventricular septum contributes to the pumping function of both ventricles. However, unlike the ventricular wall, its mechanical behavior remains largely unknown. To fill the knowledge gap, this study aims to characterize the biaxial and transmural variation of the mechanical properties of the septum and compare it to the free walls of the left and right ventricles (LV/RV). Fresh hearts were obtained from healthy, adult sheep. The septal wall was sliced along the mid-line into two septal sides and compared to the epicardial layers of the LV- and RV-free walls. Biaxial tensile mechanical tests and constitutive modeling were performed to obtain the passive mechanical properties of the LV- and RV-side of the septum and ventricular walls. We found that both sides of the septum were significantly softer than the respective ventricular walls, and that the septum presented significantly less collagen than the ventricular walls. At low strains, we observed the symmetric distribution of the fiber orientations and a similar anisotropic behavior between the LV-side and RV-side of the septum, with a stiffer material property in the longitudinal direction, rather than the circumferential direction. At high strains, both sides showed isotropic behavior. Both septal sides had similar intrinsic elasticity, as evidenced by experimental data and constitutive modeling. These new findings offer important knowledge of the biomechanics of the septum wall, which may deepen the understanding of heart physiology.

Cardiac Magnetic Resonance Imaging in Pulmonary Arterial Hypertension: Ready for Clinical Practice and Guidelines?

Purpose of Review

Pulmonary arterial hypertension (PAH) is a progressive disease with high mortality. A greater understanding of the physiology and function of the cardiovascular system in PAH will help improve survival. This review covers the latest advances within cardiovascular magnetic resonance imaging (CMR) regarding diagnosis, evaluation of treatment, and prognostication of patients with PAH.

Recent Findings

New CMR measures that have been proven relevant in PAH include measures of ventricular and atrial volumes and function, tissue characterization, pulmonary artery velocities, and arterio-ventricular coupling.

Summary

CMR markers carry prognostic information relevant for clinical care such as treatment response and thereby can affect survival. Future research should investigate if CMR, as a non-invasive method, can improve existing measures or even provide new and better measures in the diagnosis, evaluation of treatment, and determination of prognosis of PAH.

Underfilling decreases left ventricular function in pulmonary arterial hypertension

To evaluate the association between impaired left ventricular (LV) longitudinal function and LV underfilling in patients with pulmonary arterial hypertension (PAH). Thirty-nine patients with PAH and 18 age and sex-matched healthy controls were included. LV volume and left atrial volume (LAV) were delineated in short-axis cardiac magnetic resonance (CMR) cine images. LV longitudinal function was assessed from atrio-ventricular plane displacement (AVPD) and global longitudinal strain (GLS) was assessed using feature tracking in three long-axis views. LV filling was assessed by LAV and by pulmonary artery wedge pressure (PAWP) using right heart catheterisation. Patients had a smaller LAV, LV volume and stroke volume as well as a lower LV-AVPD and LV-GLS than controls. PAWP was 6 [IQR 5––9] mmHg in patients. LV ejection fraction did not differ between groups. LV stroke volume correlated with LV-AVPD (r = 0.445, p = .001), LV-GLS (r = − 0.549, p < 0.0001) and LAVmax (r = .585, p < 0.0001). Furthermore, LV-AVPD (r = .598) and LV-GLS (r = − 0.675) correlated with LAVmax (p < 0.0001 for both). Neither LV-AVPD, LV-GLS, LAVmax nor stroke volume correlated with PAWP. Impaired LV longitudinal function was associated with low stroke volume, low PAWP and a small LAV in PAH. Small stroke volumes and LAV, together with normal LA pressure, implies that the mechanism causing reduced LV longitudinal function is underfilling rather than an intrinsic LV dysfunction in PAH.

Cardiovascular disease in women: insights from magnetic resonance imaging

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.

Right ventricular function parameters in pulmonary hypertension: echocardiography vs. cardiac magnetic resonance

BACKGROUND

Right ventricular (RV) function is a major determinant of outcome in patients with pulmonary hypertension. Cardiac magnetic resonance (CMR) is gold standard to assess RV ejection fraction (RVEF_CMR), however this is a crude measure. New CMR measures of RV function beyond RVEF_CMR have emerged, such as RV lateral atrio-ventricular plane displacement (AVPD_lat), maximum emptying velocity (S'_CMR), RV fractional area change (FAC_CMR) and feature tracking of the RV free wall (FWS_CMR). However, it is not fully elucidated if these CMR measures are in parity with the equivalent echocardiography-derived measurements: tricuspid annular plane systolic excursion (TAPSE), S'-wave velocity (S'_echo), RV fractional area change (FAC_echo) and RV free wall strain (FWS_echo). The aim of this study was to compare regional RV function parameters derived from CMR to their echocardiographic equivalents in patients with pulmonary hypertension and to RVEF_CMR.

METHODS

Fifty-five patients (37 women, 62 ± 15 years) evaluated for pulmonary hypertension underwent CMR and echocardiography. AVPD_lat, S'_CMR, FAC_CMR and FWS_CMR from cine 4-chamber views were compared to corresponding echocardiographic measures and to RVEF_CMR delineated in cine short-axis stack.

RESULTS

A strong correlation was demonstrated for FAC whereas the remaining measurements showed moderate correlation. The absolute bias for S' was 2.4 ± 3.0 cm/s (relative bias 24.1 ± 28.3%), TAPSE/AVPD_lat 5.5 ± 4.6 mm (33.2 ± 25.2%), FWS 4.4 ± 5.8% (20.2 ± 37.5%) and for FAC 5.1 ± 8.4% (18.5 ± 32.5%). In correlation to RVEF_CMR, FAC_CMR and FWS_echo correlated strongly, FAC_echo, AVPD_lat, FWS_CMR and TAPSE moderately, whereas S' had only a weak correlation.

CONCLUSION

This study has demonstrated a moderate to strong correlation of regional CMR measurements to corresponding echocardiographic measures. However, biases and to some extent wide limits of agreement, exist between the modalities. Consequently, the equivalent measures are not interchangeable at least in patients with pulmonary hypertension. The echocardiographic parameter that showed best correlation with RVEF_CMR was FWS_echo. At present, FAC_echo and FWS_echo as well as RVEF_CMR are the preferred methods to assess and follow up RV function in patients with pulmonary hypertension. Future investigations of the CMR right ventricular measures, beyond RVEF, are warranted.

Decreased biventricular longitudinal strain in patients with systemic sclerosis is mainly caused by pulmonary hypertension and not by systemic sclerosis per se

Purpose

Patients with pulmonary arterial hypertension (PAH) due to systemic sclerosis (SSc) have high mortality. Left ventricular (LV) peak global longitudinal strain (GLS) is decreased in SSc. It is unknown whether low GLS is due to SSc or PAH. Therefore, our primary aim was to evaluate both LV and right ventricular free wall GLS (RVFW GLS) in SSc, with and without PAH, using cardiac magnetic resonance with feature tracking. Secondary aim was to relate GLS to invasive mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).

Methods

Thirty‐eight patients with SSc, 19 patients with SSc‐PAH and 19 healthy controls for comparison, were included. Endocardial and epicardial borders were delineated in cine images (short‐axis stack and three long‐axis views) for volumetric and strain calculations.

Results

Systemic sclerosis‐PAH had lower LV and RVFW GLS than SSc (LV: P = 0·01, RV: P<0·001) and controls (LV: P = 0·02; RV: P<0·001), with no difference between SSc and controls. LV strain correlated with mPAP (R = 0·42, P = 0·03) and PVR (R = 0·52, P = 0·006). RVFW GLS correlated with mPAP (R = 0·68, P<0·001) and PVR (R = 0·59, P = 0·001). ROC curves for predicting PAH had AUC 0·73 for LV strain (P = 0·003) and 0·86 for RVFW GLS (P<0·001).

Conclusions

Lower GLS is mainly determined by increased pulmonary pressure and not by SSc per se. Low LV and RVFW GLS are indicative of increased mPAP and PVR, which opens for improved non‐invasive methods to select patients eligible for right heart catheterization and to monitor the effects of PAH therapy.

Isolated pulmonary regurgitation causes decreased right ventricular longitudinal function and compensatory increased septal pumping in a porcine model

Aim

Longitudinal ventricular contraction is a parameter of cardiac performance with predictive power. Right ventricular (RV) longitudinal function is impaired in patients with free pulmonary regurgitation (PR) following corrective surgery for Tetralogy of Fallot (TOF). It remains unclear whether this is a consequence of the surgical repair, or whether it is inherent to PR. The aim of this study was to assess the relationship between longitudinal, lateral and septal pumping in a porcine model of isolated PR.

Methods

Piglets were divided into a control (n = 8) group and a treatment (n = 12) group, which received a stent in the pulmonary valve orifice, inducing PR. After 2–3 months, animals were subjected to cardiac magnetic resonance imaging. A subset of animals (n = 6) then underwent percutaneous pulmonary valve replacement (PPVR) with follow‐up 1 month later. Longitudinal, lateral and septal contributions to stroke volume (SV) were quantified by measuring volumetric displacements from end‐diastole to end‐systole in the cardiac short axis and long axis.

Results

PR resulted in a lower longitudinal contribution to RV stroke volume, compared to controls (60.0 ± 2.6% vs. 73.6 ± 3.8%; P = 0.012). Furthermore, a compensatory increase in septal contribution to RVSV was observed (11.0 ± 1.6% vs. −3.1 ± 1.5%; P < 0.0001). The left ventricle (LV) showed counter‐regulation with an increased longitudinal LVSV. Changes in RV longitudinal function were reversed by PPVR.

Conclusion

These findings suggest that PR contributes to decreased RV longitudinal function in the absence of scarring from cardiac surgery. Measurement of longitudinal RVSV may aid risk stratification and timing for interventional correction of PR in TOF patients.

Longitudinal shortening remains the principal component of left ventricular pumping in patients with chronic myocardial infarction even when the absolute atrioventricular plane displacement is decreased

Background

The majority (60%) of left ventricular (LV) stroke volume (SV) is generated by longitudinal shortening causing apical atrioventricular plane displacement (AVPD) in systole. The remaining SV is caused by radial inward motion of the epicardium both in the septal and the lateral wall. We aimed to determine if these longitudinal, septal and lateral contributions to LVSV are changed in patients with chronic myocardial infarction (MI).

Methods

Patients with a chronic (>3 months) ST-elevation MI in the left anterior descending (LAD, n = 20) or right coronary artery (RCA, n = 16) and healthy controls (n = 20) were examined with cardiovascular magnetic resonance (CMR). AVPD was quantified in long axis cine CMR images and LV volumes and dimensions in short axis cine images.

Results

AVPD was decreased both in patients with LAD-MI (11 ± 1 mm, p < 0.001) and RCA-MI (13 ± 1 mm, p < 0.05) compared to controls (15 ± 0 mm). However, the longitudinal contribution to SV was unchanged for both LAD-MI (58 ± 3%, p = 0.08) and RCA-MI (59 ± 3%, p = 0.09) compared to controls (64 ± 2%). The preserved longitudinal contribution despite decreased absolute AVPD was a results of increased epicardial dimensions (p < 0.01 for LAD-MI and p = 0.06 for RCA-MI). In LAD-MI the septal contribution to LVSV was decreased (5 ± 1%) compared to both controls (10 ± 1%, p < 0.01) and patients with RCA-MIs (10 ± 1%, p < 0.01). The lateral contribution was increased in LAD-MI patients (44 ± 3%) compared to both RCA-MI (35 ± 2%, p < 0.05) and controls (29 ± 2%, p < 0.001).

Conclusion

Longitudinal shortening remains the principal component of left ventricular pumping in patients with chronic MI even when the absolute AVPD is decreased.

Maternal nutrient restriction during pregnancy and lactation leads to impaired right ventricular function in young adult baboons

KEY POINTS

Maternal nutrient restriction induces intrauterine growth restriction (IUGR) and leads to heightened cardiovascular risks later in life. We report right ventricular (RV) filling and ejection abnormalities in IUGR young adult baboons using cardiac magnetic resonance imaging. Both functional and morphological indicators of poor RV function were seen, many of which were similar to effects of ageing, but also with a few key differences. We observed more pronounced RV changes compared to our previous report of the left ventricle, suggesting there is likely to be a component of isolated RV abnormality in addition to expected haemodynamic sequelae from left ventricular dysfunction. In particular, our findings raise the suspicion of pulmonary hypertension after IUGR. This study establishes that IUGR also leads to impairment of the right ventricle in addition to the left ventricle classically studied.

ABSTRACT

Maternal nutrient restriction induces intrauterine growth restriction (IUGR), increasing later life chronic disease including cardiovascular dysfunction. Our left ventricular (LV) CMRI studies in IUGR baboons (8 M, 8 F, 5.7 years - human equivalent approximately 25 years), control offspring (8 M, 8 F, 5.6 years), and normal elderly (OLD) baboons (6 M, 6 F, mean 15.9 years) revealed long-term LV abnormalities in IUGR offspring. Although it is known that right ventricular (RV) function is dependent on LV health, the IUGR right ventricle remains poorly studied. We examined the right ventricle with cardiac magnetic resonance imaging in the same cohorts. We observed decreased ejection fraction (49 ± 2 vs. 33 ± 3%, P < 0.001), cardiac index (2.73 ± 0.27 vs. 1.89 ± 0.20 l min-1 m-2 , P < 0.05), early filling rate/body surface area (BSA) (109.2 ± 7.8 vs. 44.6 ± 7.3 ml s-1  m-2 , P < 0.001), wall thickening (61 ± 3 vs. 44 ± 5%, P < 0.05), and longitudinal shortening (26 ± 3 vs. 15 ± 2%, P < 0.01) in IUGR animals with increased chamber volumes. Many, but not all, of these changes share similarities to normal older animals. Our findings suggest IUGR-induced pulmonary hypertension should be further investigated and that atrial volume, pulmonic outflow and interventricular septal motion may provide valuable insights into IUGR cardiovascular physiology. Overall, our findings reaffirm that gestational and neonatal challenges can result in long-term programming of poor offspring cardiovascular health. To our knowledge, this is the first study reporting IUGR-induced programmed adult RV dysfunction in an experimental primate model.

Time-resolved tracking of the atrioventricular plane displacement in Cardiovascular Magnetic Resonance (CMR) images

Background

Atrioventricular plane displacement (AVPD) is an indicator for systolic and diastolic function and accounts for 60% of the left ventricular, and 80% of the right ventricular stroke volume. AVPD is commonly measured clinically in echocardiography as mitral and tricuspid annular plane systolic excursion (MAPSE and TAPSE), but has not been applied widely in cardiovascular magnetic resonance (CMR). To date, there is no robust automatic algorithm available that allows the AVPD to be measured clinically in CMR with input in a single timeframe. This study aimed to develop, validate and provide a method that automatically tracks the left and right ventricular AVPD in CMR images, which can be used in the clinical setting or in applied cardiovascular research in multi-center studies.

Methods

The proposed algorithm is based on template tracking by normalized cross-correlation combined with a priori information by principal component analysis. The AVPD in each timeframe is calculated for the left and right ventricle separately using CMR long-axis cine images of the 2, 3, and 4-chamber views.

The algorithm was developed using a training set (n = 40), and validated in a test set (n = 113) of healthy subjects, athletes, and patients after ST-elevation myocardial infarction from 10 centers. Validation was done using manual measurements in end diastole and end systole as reference standard. Additionally, AVPD, peak emptying velocity, peak filling velocity, and atrial contraction was validated in 20 subjects, where time-resolved manual measurements were used as reference standard. Inter-observer variability was analyzed in 20 subjects.

Results

In end systole, the difference between the algorithm and the reference standard in the left ventricle was (mean ± SD) -0.6 ± 1.9 mm (R = 0.79), and −0.8 ± 2.1 mm (R = 0.88) in the right ventricle. Inter-observer variability in end systole was −0.6 ± 0.7 mm (R = 0.95), and −0.5 ± 1.4 mm (R = 0.95) for the left and right ventricle, respectively. Validation of peak emptying velocity, peak filling velocity, and atrial contraction yielded lower accuracy than the displacement measures.

Conclusions

The proposed algorithm show good agreement and low bias with the reference standard, and with an agreement in parity with inter-observer variability. Thus, it can be used as an automatic method of tracking and measuring AVPD in CMR.

Electronic supplementary material

The online version of this article (doi:10.1186/s12880-017-0189-5) contains supplementary material, which is available to authorized users.

Left ventricular long axis function assessed during cine-cardiovascular magnetic resonance is an independent predictor of adverse cardiac events

BACKGROUND

Left ventricular pump function requires a complex interplay involving myocardial fibers orientated in the longitudinal, oblique and circumferential directions. Long axis dysfunction appears to be an early marker for a number of pathological states. We hypothesized that mitral annular plane systolic excursion (MAPSE) measured during cine-cardiovascular magnetic resonance (CMR) reflects changes in long axis function and may be an early marker for adverse cardiovascular outcomes. The aims of this study were therefore: 1) To assess the feasibility and reproducibility of MAPSE measurements during routine cine-CMR; and 2) To assess whether MAPSE, as a surrogate for long axis function, is a predictor of major adverse cardiovascular events (MACE).

METHODS

Four hundred consecutive patients undergoing CMR were prospectively enrolled. MAPSE was measured in the 4-chamber cine view. Patients were prospectively followed for major adverse cardiac events (MACE) - death, non-fatal myocardial infarction, hospitalization for heart failure or unstable angina, and late revascularization. Cox proportional hazards regression modeling was used to identify factors independently associated with MACE. Net reclassification improvement (NRI) was calculated to assess whether addition of MAPSE resulted in improved risk reclassification of MACE.

RESULTS

Seventy-two MACE occurred during a median follow-up of 14.5 months. By Kaplan-Meier analysis, patients with lateral MAPSE <1.11 cm (median) experienced significantly higher incidence of MACE than patients with a MAPSE ≥1.11 cm (p = 0.027). After adjustment for established clinical risk factors which were univariate predictors (age, diabetes, hypertension, NYHA class, LV mass), lateral MAPSE remained a significant independent predictor of MACE (HR = 4.384 per cm decrease or 1.344 per 2 mm decrease; p = 0.020). Incorporation of lateral MAPSE into this risk model resulted in a net reclassification improvement (NRI) of 0.18 (p = 0.006).

CONCLUSIONS

Reduced long axis function assessed with lateral MAPSE during cine-CMR is an independent predictor of MACE.