Christensen, Nicolaj Lyhne

Background Haemodynamic exercise testing is important for evaluating patients with dyspnoea on exertion and preserved ejection fraction. Despite very different pathologies, patients with pressure (aortic stenosis (AS)) and volume (mitral regurgitation (MR)) overload and diastolic dysfunction after recent acute myocardial infarction (AMI) reach similar filling pressure levels with exercise. The pressure–flow relationships (the association between change in cardiac output (∆CO) and change in pulmonary arterial wedge pressure (∆PAWP) may provide insight into haemodynamic adaptation to exercise in these groups. Methods and results One hundred sixty-eight subjects aged >50 years with a left ventricular ejection fraction of ≥50% underwent invasive exercise testing. They were enrolled in four different studies: AS (40 patients), AMI (52 patients), MR (43 patients) and 33 healthy subjects. Haemodynamic data were measured at rest, at 25 W, 75 W and at peak exercise. In all groups, PAWP increased with exercise. The greatest increase was observed in patients with AMI (from 12.7±3.9 mm Hg to 33.1±8.2 mm Hg, p<0.0001) and patients with AS (from 11.8±3.9 mm Hg to 31.4±6.1 mm Hg, p<0.0001), and the smallest was observed in healthy subjects (from 8.3±2.4 mm Hg to 21.1±7.5 mm Hg, p<0.0001). In all groups, the relative pressure increase was greatest at the beginning of the exercise. CO increased most in healthy patients (from 5.3±1.1 to 16.0±3.0 L/min, p<0.0001) and least in patients with AS (from 5.3±1.2 L/min to 12.4±2.6 L/min, p<0.0001). The pressure–flow relationships (∆PAWP/∆CO) and differed among groups (p = 0.02). In all groups, the pressure–flow relationship was steepest in the initial phase of the exercise test. The AMI and AS groups (2.3±1.2 mm Hg/L/min and 3.0±1.3 mm Hg/L/min, AMI and AS, respectively) had the largest overall pressure–flow relationship; the healthy group had the smallest initially and at peak exercise (1.3±1.1 mm Hg/L/min) followed by MR group (1.9±1.4 mm Hg/L/min). Conclusion The pressure–flow relationship was steepest in the initial phase of the exercise test in all groups. The pressure–flow relationship differs between groups. Trial registration numbers NCT01974557 , NCT01046838 , NCT02961647 and NCT02395107 .

Background First-phase ejection fraction (EF1), the left ventricular (LV) ejection fraction (EF) until the time of peak transaortic velocity, is a novel marker of subclinical LV dysfunction able to predict adverse events in aortic stenosis (AS). This study investigated the association between end-systolic wall stress (ESWS) and EF1 in severe AS, as well as the prognostic value of EF1 in severe asymptomatic AS. Methods Two prospectively gathered cohorts of 94 asymptomatic patients and 108 symptomatic patients scheduled for aortic valve replacement (AVR), all with severe AS (aortic valve area <1 cm2) were stratified according to the median value of EF1 (33%). EF1 was defined as the EF at peak transaortic velocity. Asymptomatic patients were followed up for 3 years for the combined end-point of death, AVR or admission with heart failure. Results EF1 correlated with EF and was inversely associated with ESWS. In multivariate regression analysis, ESWS (p<0.001) and replacement fibrosis measured by MRI (p=0.02) were associated with EF1. Among asymptomatic patients, EF1 above the median was associated with the combined primary endpoint (HR=0.53 (95% CI 0.33 to 0.87)), while global longitudinal strain and EF were not. Among 42 patients with discordant AS (mean gradient <40 mm Hg), EF1 above median was associated with the primary endpoint (HR 0.28 (95% CI 0.12 to 0.61)). Conclusion EF1 is an afterload-dependent measure that is associated with events in patients with asymptomatic severe AS. The afterload dependency of EF1 may be useful in timing of risk stratification in patients with discordant AS. Trial registration numbers NCT02395107 and NCT02316587.

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Danish Heart Association. Background First-phase ejection fraction (EF1), the ejection fraction (EF) until the time of peak systolic flow may be a sensitive marker of subclinical left ventricular (LV) dysfunction. This study investigated the prognostic value of EF1 in asymptomatic and symptomatic severe aortic stenosis (AS). Methods This study included 94 asymptomatic and 108 symptomatic patients with severe AS. The prognostic value of EF1 was compared with other echocardiographic markers and magnetic resonance imaging (MRI) measured end-systolic wall stress and late gadolinium enhancement fibrosis (LGE). Asymptomatic patients were followed up for 3.0 years (primary outcome death or aortic valve replacement). Symptomatic patients were followed up for 4.3 years (primary outcome death). Results In multivariate regression analysis wall stress (p &lt; 0.001) and LGE (p = 0.03) were associated with EF1. In the asymptomatic cohort EF1 was significantly associated with the end-point, especially among the subgroup of patients with a mean gradient &lt; 40 mmHg (HR 0.91, p = 0.005), while global longitudinal strain was not. In the surgical cohort, EF1 was borderline associated with death (p = 0.08) which was significant after correction for LGE (HR 0.90, p = 0.02). Conclusion EF1 is a predictor of death or AVR in asymptomatic AS, especially among discordantly graded patients with low area and low gradient. Univariate β (95% CI) p-value Multivariate β (95% CI) p-value Age (years) .03 (-.09 to .16) 0.58 .03 (-.12 to .18) 0.69 Sex (male) -.12 (-2.26 to 2.03) 0.91 .24 (-2.31 to 2.80) 0.85 Hypertension -.08 (-2.22 to 2.07) 0.95 Aortic valve area (0.01 cm2) .09 (.04 to .14) 0.001 Aortic mean gradient (mmHg) -.02 (-.08 to .04) 0.56 LV end-diastolic volume (ml) -.07 (-.11 to -.03) &lt;0.001 LV end-systolic volume (ml) -.17 (-.22 to -.12) &lt;0.001 -.07 (-.15 to .02) 0.11 LV ejection fraction (%) .28 (.19 to .38) &lt;0.001 LV peak ejection time (ms) -.07 (-.16 to .02) 0.13 LGE fibrosis -3.04 (-5.67 to -.42) 0.02 -2.64 (-4.99 to -.30) 0.03 Wall stress (kdynes/m3) -.10 (-.13 to -.08) &lt;0.001 -.08 (-.12 to -.04) &lt;0.001 Multivariate linear regression analysis for associations with first phase ejection fraction. LV is left ventricular, LGE late gadolinium enhancement Abstract Figure. AVR-free survival according to EF1

Background— In severe asymptomatic primary mitral valve regurgitation without risk factors, surgery strategy is controversial. We sought to clarify whether being symptomatic corresponds to the hemodynamic burden and reduced exercise capacity. A better understanding of this may contribute to optimize timing of surgery. Methods and Results— Subjects with asymptomatic (New York Heart Association functional class I, n=29) or symptomatic (New York Heart Association functional class II and III, n=28) significant primary mitral valve regurgitation (effective regurgitant orifice, ≥0.30 cm 2 ; left ventricular ejection fraction, >60%) were included. Right heart catheterization during rest and exercise, echocardiography, magnetic resonance imaging, and peak oxygen consumption test was performed. Symptomatic subjects had significantly higher pulmonary capillary wedge pressure at rest (14±4 versus 11±3 mm Hg; P =0.003) and at maximal exercise (30±6 versus 25±7 mm Hg; P =0.02) and higher mean pulmonary artery pressure (PAP) at rest (22±7 versus 18±4 mm Hg; P =0.005) and maximal exercise (46±8 versus 39±7 mm Hg; P =0.005) than asymptomatic subjects. Among asymptomatic subjects with normal resting value, exercise testing revealed a systolic PAP >60 mm Hg in 34%. Also the reverse response with minimal increase in pulmonary capillary wedge pressure and mean PAP during exercise was seen, especially in asymptomatic subjects. Among symptomatic subjects, we found a significant inverse correlation between resting mean PAP and left ventricular ejection fraction ( r =−0.52; P =0.02) and right ventricular ejection fraction ( r =−0.67; P <0.01). Peak oxygen consumption was equal and normal in both groups and correlated with left ventricular stroke volume but not with pulmonary capillary wedge pressure. Conclusions— Symptoms in patients with severe mitral valve regurgitation relate to congestion (pulmonary capillary wedge pressure and PAP), but not to peak oxygen consumption, which is determined by forward left ventricular stroke volume. Exercise testing reveals a higher mitral valve regurgitation burden in apparently asymptomatic patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT02961647.

Background— In aortic valve stenosis (AS), the occurrence of heart failure symptoms does not always correlate with severity of valve stenosis and left ventricular (LV) function. Therefore, we tested the hypothesis that symptomatic patients with AS have impaired diastolic, longitudinal systolic function, and left atrial dilatation compared with asymptomatic patients. Methods and Results— In a retrospective descriptive study, we compared clinical characteristics and echocardiographic parameters in 99 symptomatic and 139 asymptomatic patients with severe AS and LV ejection fraction ≥50%. Independent predictors of symptomatic state were identified using logistic regression analysis. Symptomatic patients were younger (72±10 versus 76±12 years of age; P =0.002), presented less often with atrial fibrillation (13% versus 24%; P =0.05) and chronic obstructive pulmonary disease (2% versus 19%; P <0.001), and had a lower prevalence of hypertension (73% versus 40%; P <0.001). Despite similar AS severity, symptomatic patients had higher LV mass index (120±39 versus 95±25 g/m 2 ; P <0.0001), increased relative wall thickness (0.61±0.15 versus 0.50±0.11; P <0.0001), shorter mitral deceleration time (199±58 versus 268±62 ms; P <0.0001), and increased left atrial volume index (49±18 versus 42±15 mL/m 2 ; P =0.02). When adjusting for age, history of hypertension, atrial fibrillation, and chronic obstructive pulmonary disease in a multivariable logistic regression analysis, LV mass index, relative wall thickness, left atrial volume index, and deceleration time were still associated with the presence of symptoms. Conclusions— The present study demonstrates that symptomatic status in severe AS is associated with impaired diastolic function, LV hypertrophy, concentric remodeling, and left atrial dilatation when corrected for indices of AS severity. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00294775.