Citations

Background: Because of limited accuracy of noninvasive tests, diastolic stress testing plays an important role in the diagnostic work-up of patients with heart failure with preserved ejection fraction (HFpEF). Exercise right heart catheterization is considered the gold standard and indicated when HFpEF is suspected but left ventricular filling pressures at rest are normal. However, performing exercise during right heart catheterization is not universally available. Here, we examined whether pulmonary capillary wedge pressure (PCWP) during a passive leg raise (PLR) could be used as simple and accurate method to diagnose or rule out occult-HFpEF. Methods: In our tertiary center for pulmonary hypertension and HFpEF, all patients who received a diagnostic right heart catheterization with PCWP-measurements at rest, PLR, and exercise were evaluated (2014–2020). The diagnostic value of PCWP PLR was compared with the gold standard (PCWP EXERCISE ). Cut-offs derived from our cohort were subsequently validated in an external cohort (N=74). Results: Thirty-nine non-HFpEF, 33 occult-HFpEF, and 37 manifest-HFpEF patients were included (N=109). In patients with normal PCWP REST (<15 mmHg), PCWP PLR significantly improved diagnostic accuracy compared with PCWP REST (AUC=0.82 versus 0.69, P =0.03). PCWP PLR ≥19 mmHg (24% of cases) had a specificity of 100% for diagnosing occult-HFpEF, irrespective of diuretic use. PCWP PLR ≥11 mmHg had a 100% sensitivity and negative predictive value for diagnosing occult-HFpEF. Both cut-offs retained a 100% specificity and 100% sensitivity in the external cohort. Absolute change in PCWP PLR or V-wave derived parameters had no incremental value in diagnosing occult-HFpEF. Conclusions: PCWP PLR is a simple and powerful tool that can help to diagnose or rule out occult-HFpEF.

Introduction: Obesity is common in heart failure with preserved ejection fraction (HFpEF) and is directly linked with lower levels of physical activity (PA). Visceral adiposity (VAT) is more common in HFpEF than controls and may play a role in its pathogenesis, characterized by impaired exercise capacity (peak VO 2 ). The direct relationship between VAT and PA in HFpEF is unknown. Hypothesis: Compared to controls, HFpEF patients will have excess regional adiposity (VAT, subcutaneous (SAT), and intramuscular (IMAT)), and these fat depots will be associated with lower levels of chronic physical activity. Methods: HFpEF patients (n=51; age 70±9) and non-HFpEF controls (n=49; age 65±5) prospectively underwent body composition measurement by dual-energy x-ray absorptiometry and magnetic resonance imaging. Peak VO 2 was measured by standard cardiopulmonary exercise testing. PA was monitored continuously via accelerometry over two weeks. Data were binned in arbitrary accelerometry units, averaged and stored in 30-second epochs (counts per epoch, CPE). Models were adjusted for age, sex, and ideal body weight. Results: HFpEF were less active overall (3.15±0.80 vs 3.59±0.73 CPE), had less moderate intensity PA (10.13±0.04 vs 10.15±0.03 CPE), and less morning (3.83±1.15 vs 4.24±1.09 CPE) and afternoon (3.84± 1.20 vs 4.53± 0.97 CPE) (p<0.05 for all) PA. Patients with HFpEF spent a greater proportion of time sedentary (0.71±0.08 vs 0.67±0.08 CPE) and less time in moderate (0.04±0.03 vs 0.06±0.03 CPE) and vigorous (0.02±0.01 vs 0.03±0.03 CPE) PA (p<0.01 for all). Chronic PA was significantly associated with regional fat depots (VAT β= -0.003, 95% CI: -0.004-0.001; SAT β= -0.003, 95%CI: -0.004-0.001; IMAT β=-0.02, 95% CI: -0.04—0.01) as a combined cohort (p<0.01 for all). Muscle quality (β=0.28, 95%CI: 0.15-0.40), peak VO 2 (β=0.08, 95% CI: 0.03-0.13), and peak watts (β=0.01, 95% CI: -0.004-0.02) were associated with PA in HFpEF only (p≤0.01 for all). Conclusions: The amount and pattern of PA differs between HFpEF and controls, as do relationships between regional fat depots and PA, and the relationship of PA and peak VO 2 . Further investigation is needed to better understand the temporality and mechanisms related to the pathophysiology and severity of HFpEF.

Introduction: Obesity is prevalent in HFpEF, a syndrome that disproportionality affects women, and is associated with poor exercise tolerance (VO 2 ), reduced quality of life, and greater symptoms. Visceral adipose tissue (VAT), more than general obesity, is related to metabolic and cardiovascular dysfunction common to HFpEF. While fat deposition varies between sexes, these differences and the relation to exercise tolerance remain unclear in HFpEF. Hypothesis: Compared to sex-matched controls, HFpEF patients will demonstrate reduced lean mass, excess VAT, subcutaneous, visceral, and intramuscular fat, and will be associated with reduced VO 2 . Methods: HFpEF females (F) and males (M) (n=78; 37 F/41 M; age 70±9) and non-HFpEF controls (n=50; 30 F/20 M; age 65±5) prospectively underwent body composition measurement via dual-energy x-ray absorptiometry and magnetic resonance imaging (MRI) and cardiopulmonary exercise testing for measurement of peak oxygen consumption (peak VO 2 ). Muscle quality calculated as peak Watts (W) achieved divided by MRI thigh lean mass. Results: HFpEF had greater VAT, subcutaneous (SAT) and intramuscular (IMAT), and poorer muscle quality than controls (all p<0.01). Exercise performance was lower in HFpEF (peak VO 2 : 14±4 vs. 22±6; peak W: 69±29 vs. 116±34; both p<0.01). HFpEF demonstrated increased odds for VAT (OR: 2.02, 95% CI: 1.22-3.37), SAT (OR: 2.05, 95% CI: 1.20-3.49), and IMAT (OR: 2.04, 95% CI: 1.35-3.39) (all p<0.01). Sex-stratification revealed increased odds of excess VAT in HFpEF females (OR: 2.76, 95% CI: 1.16-7.72, p=0.03), SAT in HFpEF males (OR: 3.64, 95% CI: 1.10-12.07, p=0.03), and IMAT in HFpEF females (OR: 2.38, 95%CI: 1.10-5.29, p=0.03) with a trend in males (OR: 1.67, 95%CI: 0.97-2.86, p=0.06). Impaired VO 2 was associated with all AT depots as a combined cohort and among controls (all p<0.01) and linked to poor muscle quality individually for men and women in HFpEF and controls (all p<0.01). Conclusion: HFpEF patients have significantly altered body composition profiles and reduced exercise tolerance compared to controls. Sex differences in regional fat deposition impact peak VO 2 and may serve a distinct role in the pathophysiology of HFpEF.

Introduction: Pulmonary hypertension (PH), defined as an elevated mean pulmonary artery pressure, has been consistently associated with adverse outcomes in hospitalized patients. Limited epidemiologic data exist regarding PH in the cardiac intensive care unit (CICU) population. We used transthoracic echocardiography (TTE) to describe the prevalence, etiology, and outcomes of PH in the CICU. Hypothesis: PH will be associated with higher in-hospital mortality in CICU patients. Methods: CICU patients admitted from 2007 to 2018 who had right ventricular systolic pressure (RVSP) measured via TTE within 1 day of CICU admission were included. PH was defined as an estimated RVSP >35 mmHg. Predictors of in-hospital mortality were determined using multivariable logistic regression. Results: We included 5042 patients with a mean age of 69.4±14.8 (41% females); 81.1% had an admission diagnosis of acute coronary syndrome or heart failure. PH was present in 3085 (61%); the majority (68%) of patients with PH had left heart failure, and 29% had lung disease. In-hospital mortality occurred in 8% and was higher in patients with PH (11% vs. 4%, adjusted OR 1.40, 95% CI 1.03-1.92, p =0.03). PH was associated with higher in-hospital mortality in patients with acute coronary syndrome, heart failure or cardiac arrest (all p <0.01), but not in patients with cardiogenic shock, respiratory failure or sepsis ( Figure ). In-hospital mortality increased as a function of higher RVSP in each admission diagnosis group (adjusted 1.18 per 10 mmHg higher in the entire cohort, 95% CI 1.09-1.28, p <0.001). Conclusions: PH by TTE is very common in the CICU population and remains associated with a higher risk of death during hospitalization even after adjustment. TTE assessment of right heart hemodynamics can predict mortality in CICU patients, with variability across common admission diagnoses. This highlights the importance of PH determined by TTE in hospitalized patients with cardiac critical illness.

Background: The relationship between blood volume and pressure in the vascular system can be described in terms of unstressed and stressed blood volume. Stressed blood volume determines venous pressure and provides preload back to the heart, which regulates the generation of cardiac output (CO) via the Frank-starling mechanism. Whether sodium-glucose cotransporter-2 (SGLT2i) favorably modifies stressed blood volume is not known. Hypothesis: To investigate the effect of SGLT2i (empagliflozin) on the hemodynamic estimated stressed blood volume (eSBV) in HFrEF patients compared to placebo. Methods: A post hoc analysis of investigator-initiated, double-blinded, placebo-controlled, randomized trial. Seventy patients were assigned to empagliflozin of 10 mg or matching placebo once daily for 12 weeks. Patients underwent right heart catheterization at rest and during exercise at baseline and follow-up. Outcome was change in eSBV after 12 weeks of empagliflozin treatment at each level of exercise. We conducted computer-modelling simulations based on invasive hemodynamic assessment to measure eSBV. Results: HFrEF patients with mean age was 57 years, mean ejection fraction 27%, 47 (71%) on diuretics were randomized. After 12 weeks treatment exercise eSBV was significantly reduced at 0 watt, 25 watt and 25 % of maximal exercise watt, compared to placebo [(0 watt; –258 mL, 95% CI –476 to –39, p=0.021); (25 watt; –301 mL, 95% CI –561 to –40, p=0.024); and (25% of peak exercise watt; –262 mL, 95% CI –490 to –34, p=0.024)]. There was no effect on rest, or at peak exercise eSBV [(Rest; –75 ml, 95% confidence interval [CI] –279 to 130; p=0.47); and (Peak; –96 mL, 95% CI –444 to 251, p=0.59)]. This was consistent among patients with and without type 2 diabetes, etiology of HFrEF, and diuretic usage (Figure 1). Conclusion: Empagliflozin may contribute to shift blood from the effective circulatory beds to the venous reservoir in reducing filling pressure and eSBV, but maintaining CO.

Introduction: Peripheral factors contribute to exercise limitations in heart failure (HF) with preserved ejection fraction (HFpEF) and may be related to excess regional adiposity. Slowed oxygen uptake (VO 2 ) kinetics are common in HF with reduced ejection fraction (HFrEF) and reflect peripheral O 2 transport impairments and abnormal muscle metabolic control. Differences in VO 2 kinetics between HFpEF and HFrEF may reveal phenotype-specific impairments in peripheral O 2 transport but remain unknown. Hypothesis: We hypothesized that VO 2 kinetics are slower in HFpEF (compared to HFrEF) and associated with greater leg adiposity. Methods: Patients with HFpEF (n=12; 3 women; 66±6 yrs; 29±3 kg/m 2 ; ejection fraction: 59±5%), HFrEF (n=12; 3 women; 62±9 yrs; 28±4 kg/m 2 ; ejection fraction: 37±8%), and controls (n=12; 3 women; 65±5 yrs; 28±3 kg/m 2 ) cycled at 20 W for 5 minutes prior to a maximal exercise test to determine VO 2peak . Age, sex, and BMI were matched by design and were not different among groups (p>0.05). A monoexponential function with a time delay was used to describe the VO 2 transition from rest to 20 W and calculate the O 2 deficit. Leg fat mass was measured via dual energy X-ray absorptiometry. Results: VO 2peak was lower in HFpEF (18.6±6.2 mL/kg/min) and HFrEF (19.0±3.7 mL/kg/min) compared to controls (26.0±3.1; both p<0.05). Amplitude (HFpEF: 507±97 mL/min; HFrEF: 443±91 mL/min; controls: 477±117 mL/min) and time delay (HFpEF: 16±9 s; HFrEF: 11±7 s; controls: 11±6 s) were not different among groups (p>0.05). The time constant was slower in HFrEF compared to controls (45±9 s vs. 32±6 s; p=0.03) and further slowed in HFpEF (66±18 s; p<0.001). The O 2 deficit was significantly greater in HFpEF (895±201 mL) and HFrEF (649±131 mL) compared to controls (590±125 mL; both p<0.05). There were no differences in percent leg fat mass among groups (HFpEF: 33±8%; HFrEF: 31±6%; controls: 34±9%) and no associations were detected between percent leg fat mass and any VO 2 parameters (all p>0.05). Conclusions: Patients with HFpEF exhibited slower VO 2 kinetics compared to HFrEF with no association to leg adiposity. These data suggest differences in peripheral O 2 transport and intramuscular metabolic control abnormalities between HF phenotypes.

Introduction: Heart failure patients with preserved ejection fraction (HFpEF) may exhibit inspiratory muscle dysfunction potentially contributing to exercise intolerance. Activation of neural afferents in response to inspiratory muscle contraction (metaboreflex) elicits increases in mean arterial pressure (MAP) and leg vascular resistance (LVR) through enhanced sympathetic outflow leading to decreases in leg blood flow (LBF) in healthy humans. It is unknown if HFpEF patients exhibit exaggerated cardiovascular responses to inspiratory muscle metaboreflex activation. Hypothesis: We hypothesize that patients with HFpEF will exhibit a greater increase in MAP and LVR with a decrease in LBF during inspiratory muscle metaboreflex activation than controls. Methods: HFpEF patients (n=15, 10M/5W, 69±10 yrs; 33±4 kg/m2) and controls (n=14; 10M/4W; 70±8 yrs; 28±4 kg/m2) performed inspiratory resistive breathing tasks (IRBT) at 2% and 60% of their maximal inspiratory pressure. During the IRBTs, the breathing frequency was 20 breaths/min with a 50% duty cycle. At rest and during the IRBTs, MAP was measured by photoplethysmography, venous norepinephrine was measured, LBF was measured by near-infrared spectroscopy and indocyanine green dye injections, and LVR was calculated. Results: During the 2% IRBT, there were no differences between groups in the changes from rest in MAP (HFpEF: 2±4 vs. CTL: 3±4 mmHg) or LBF (HFpEF: 1±14 vs. CTL: 1±12%) (both, p>0.05). During the 60% IRBT, venous norepinephrine increased from rest in HFpEF and controls (p<0.05), while no differences existed between groups (p>0.05). During the 60% IRBT, HFpEF patients, compared to controls, exhibited a greater increase from rest in MAP (HFpEF: 16±7 vs. CTL: 10±6 mmHg) and LVR (HFpEF: 76±45 vs. CTL: 32±19%) coupled with a greater decrease in LBF (HFpEF: -32±14 vs. CTL: -17±9%) (all, p<0.05). Conclusions: These data indicate that patients with HFpEF exhibit exaggerated cardiovascular responses with inspiratory muscle metaboreflex activation compared to healthy individuals. These findings have important implications for the integrative physiology of exercise in HFpEF patients.

Introduction: Arteriovenous fistulas(AVF) have been associated with high output heart failure but little is known about their effect on patients initiating hemodialysis. We sought to describe echocardiographic changes and identify those with incident heart failure after AVF creation. Methods: This was a retrospective analysis of all patients undergoing AVF creation over a 15 year period from 2000-2014 at the Mayo Clinic in Rochester, MN. Patients undergoing echocardiogram <3 months (median 40 days) before AVF creation and >6 months (median 2.5 years) following surgery were included. Patients with independent modifiers of LV structural changes (such as revascularization or myocardial infarction) were excluded by chart review. Clinical heart failure was defined by Framingham criteria. Results: From 2000-2014, 2236 patients underwent creation of AVFs and 137 patients met inclusion criteria. There was a longitudinal decrease in systolic function as evident by a drop in ejection fraction(-2%, p=0.047) with decrease in s’ tissue Doppler velocity(-0.6 cm/s, p=0.055) and increase in HR(+5 beats/min, p=0.003). There was also an increase in the prevalence of RV dilation(20 to 40%, p=0.002) and RV dysfunction(12 to 29%, p=0.002). With initiation of dialysis and decrease in weight (-7.3kg) and estimated plasma volume (-303ml) (both p<0.0001), there was a decrease in LV end diastolic dimension (-2mm, p=0.006). Despite better volume control, left atrial volume index increased (+5ml/m2, p=0.004). On multivariate Cox regression, worsening RV dilation [HR 1.8 (1.06-3.09),p=0.03] was independently associated with mortality. Incident heart failure developed in 43%(28/65) with no pre-existing HF, of whom 75% had HFPEF and 25% HFrEF. The development of new systolic HF (but not HFPEF) was associated with increased age and sex adjusted mortality [HR 3.0(1.0-7.9), p=0.045]. Conclusions: AVF creation is associated with worsening biventricular function and left atrial and RV dilatation, despite reduction in LV size. These changes are coupled with high incidence of new, unexplained heart failure. Further research is needed to identify the hemodynamic mechanisms underlying heart failure development in patients with ESRD requiring dialysis access.

Introduction: The incidence of heart failure (HF) is higher in black than in white Americans, but the causes are unclear. We proposed that ethnic differences in ventricular-arterial interaction may contribute to this differential HF risk. Methods: We studied measures of arterial elastance (Ea) and left ventricle (LV) end-systolic elastance (Ees) in 5767 community-based elderly participants (76±5 years, 41% male, 22% black) who underwent echocardiography in the Atherosclerosis Risk in Community (ARIC) Study. Results: Black participants were more frequently women (66 vs 57%) and had a higher prevalence of obesity (46 vs 31%), hypertension (94 vs 80%), and diabetes mellitus (47 vs 34%). Adjusting for these baseline differences, the prevalence of LV hypertrophy was similar, but Ea, Ees and Ea/Ees ratio were higher in blacks than whites, particularly in black women (Figure). Ea was positively associated with LV mass index and E/e’ ratio in blacks, but not in whites (p for interaction < 0.001). Conclusion: These community-based data demonstrate that ventricular-arterial stiffening is greater in black than white Americans, coupled with more ventricular remodeling and dysfunction. The heightened afterload dependence in blacks suggests greater potential for risk reduction with anti-hypertensive therapy.

Introduction: Assessment of cardiac function during exercise is critical in the clinical evaluation of patients with heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction. Direct invasive measurement of cardiac power (CP) and stroke work (SW) are robust measures of cardiac function. Non-invasive gas exchange based surrogates may provide practical means of assessing cardiac function in clinical and research settings; however, the relationship between invasive and non-invasive measurement of CP or SW during exercise is unclear in HFpEF and HFrEF. We aimed to assess relationships between invasive and non-invasive measures of CP and SW during exercise in HFpEF and HFrEF. Methods: HFpEF (n=47) and HFrEF (n=29) (age 71±10 vs 55±10 yrs; EF% 62±8 vs 21±6%; BSA 2.1±0.3 vs 2.1±0.2 m 2 ; weight 99±22 vs 87±15 kg; peak work 36±14 vs 37±13 watts (W), respectively; all p<0.05, except peak work) underwent peak exercise testing during right heart catheterization. Invasive measurement of cardiac pressures, hemodynamics, and arterial pressures were recorded at rest, 20 W, and peak work. Continuous measurement of HR and VO 2 occurred from rest to peak work via 12-lead ECG and metabolic measurement system, respectively. Invasive measurements were calculated as, CP=(MAP–RAP) x Q x 2.22х10 -3 ; SW=(MAP–PCWP) x SV I x 0.133; and non-invasive as, CP=VO 2 x MAP; SW=VO 2 /HR x MAP. All indices adjusted for body surface area. Results: At rest, there were moderate relationships between invasive and non-invasive measures of CP and SW in HFpEF (r=0.56 and 0.48) and HFrEF (0.57 and 0.73), respectively (all p<0.05). At 20 W, relationships between invasive and non-invasive measures of CP and SW strengthened in HFpEF (r=0.74 and 0.69) and HFrEF (0.74 and 0.72), respectively (all p<0.05). The relationships noted between invasive and non-invasive measures of CP and SW at 20 W persisted at peak work in HFpEF (r=0.74 and 0.67) and HFrEF (0.78 and 0.69), respectively (all p<0.05). Conclusion: These data suggest that non-invasive estimates of CP and SW correlate closely with invasive measures and may be reasonable surrogates for these indices during peak exercise testing in both HFpEF and HFrEF patients.