Continuous-flow ventricular assist device (cfVAD) performance and patient hemodynamic conditions are intimately interrelated and dynamic, changing frequently with alterations in physiologic ...conditions, particularly pre- and afterloading conditions. The Heartware cfVAD (HVAD) provides a unique feature among currently approved VADs of providing an estimated instantaneous flow waveform, the characteristics of which can provide significant insights into patient and device properties. Despite being readily available, HVAD waveforms are poorly understood, underutilized, and insufficiently leveraged, even by clinicians who regularly manage HVAD patients. The purpose of this review is to provide the theoretical foundation for understanding the determinants of HVAD waveform characteristics and to provide practical examples illustrating how to interpret and integrate changes of HVAD waveforms into clinical practice. Heartware cfVAD waveforms should be considered a complimentary tool for the optimization of medical therapies and device speed in HVAD patients.
Recent studies suggest that Doppler echocardiography (DE)-based estimates of pulmonary artery systolic pressure (PASP) may not be as accurate as previously believed. We sought to determine the ...accuracy of PASP measurements using DE compared with right-sided heart catheterization (RHC) in patients with pulmonary hypertension (PH).
We compared DE estimates of PASP to invasively measure PASP during RHC in 160 consecutive patients with PH (part one). To account for possible changes in hemodynamics between DE and RHC, we then prospectively determined PASP in an additional 23 consecutive patients undergoing simultaneous RHC and DE (part two). Bland-Altman analyses were performed to evaluate the agreement between RHC and DE measurements of PASP. Accuracy was predefined as 95% limits of agreement within ± 10 mm Hg for PASP estimates.
In part one, there was moderate correlation between DE and RHC measurements of PASP (r = 0.68, P < .001). However, using Bland-Altman analysis, the bias for DE estimates of PASP was 2.2 mm Hg with 95% limits of agreement ranging from -34.2 to 38.6 mm Hg. DE estimates of PASP were determined to be inaccurate in 50.6% of patients. In part two, there was moderate correlation between DE and RHC measurements of PASP (r = 0.71, P < .01). However, despite simultaneous DE and RHC measurements, the bias for DE estimates of PASP was 8.0 mm Hg with 95% limits of agreement ranging from -28.4 to 44.4 mm Hg.
DE estimates of PASP are inaccurate in patients with PH and should not be relied on to make the diagnosis of PH or to follow the efficacy of therapy.
Heart failure with preserved ejection fraction (HFpEF), which currently represents approximately 50 % of heart failure (HF) cases, is common and associated with high morbidity and mortality. ...Understanding the epidemiology of HFpEF has been difficult due to the challenges in HFpEF diagnosis and the heterogeneous etiologies and pathophysiologies that underlie HFpEF. Nevertheless, several high-quality epidemiology and observational registry studies of HFpEF demonstrate that an increasing prevalence of HFpEF in both the outpatient and inpatient settings, coupled with a lack of evidence-based effective treatments for HFpEF, is resulting in an emerging epidemic of HFpEF. In this review, we discuss the emerging HFpEF epidemic, focusing on: (1) reasons for the rising prevalence of HFpEF; (2) the abnormalities in cardiac structure and function that dictate the transition from risk factors to HFpEF; (3) novel HFpEF mechanisms that may underlie the increase in HFpEF prevalence; (4) prognosis of HFpEF; and (5) risk prediction in HFpEF. We conclude with 10 unanswered questions on HFpEF epidemiology that will be important areas for future investigation.
Background The Meta-Analysis Global Group in Chronic Heart Failure ( MAGGIC ) mortality risk score, derived from a large sample of patients with heart failure ( HF ) across the spectrum of ejection ...fraction ( EF ), has not yet been externally validated in a well-characterized HF with preserved EF cohort with adjudicated morbidity outcomes. Methods and Results We evaluated the MAGGIC risk score (composed of 13 clinical variables) in 407 patients with HF with preserved EF enrolled in a prospective registry and used Cox regression to evaluate its association with morbidity/mortality. We used receiver-operating characteristic analysis to compare the predictive ability of the MAGGIC risk score with the more complex Seattle Heart Failure Model, and we determined the value of adding B-type natriuretic peptide to the MAGGIC risk score for risk prediction. During a mean follow-up time of 3.6±1.8 years, 28% died, 32% were hospitalized for HF , and 55% had a cardiovascular hospitalization and/or death. The MAGGIC score, a mean± SD of 18±7, was significantly associated with mortality ( P<0.0001), HF hospitalizations ( P<0.0001), and the combined end point of cardiovascular-related hospitalizations or death (hazard ratio, 1.8 95% confidence interval, 1.6-2.1, per 1- SD increase in the MAGGIC score; P<0.0001). Receiver-operating characteristic analyses showed that MAGGIC and Seattle Heart Failure Model performed similarly in predicting HF with preserved EF outcomes, but the MAGGIC score demonstrated better calibration for hospitalization outcomes. Further analyses showed that B-type natriuretic peptide was additive to the MAGGIC risk score for predicting outcomes ( P<0.01 by likelihood ratio test). Conclusions The MAGGIC risk score is a simple, yet powerful method of risk stratification for both morbidity and mortality in HF with preserved EF . Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01030991.
Background Accurate measurement of left ventricular filling pressure is important to distinguish between category 1 pulmonary arterial hypertension (PAH) and category 2 pulmonary hypertension (PH) ...from left heart diseases (PH-HFpEF). We hypothesized that the common practice of relying on the digitized mean pulmonary capillary wedge pressure (PCWP-digital) results in erroneous recordings, whereas end-expiratory PCWP measurements (PCWP–end Exp) provide a reliable surrogate measurement for end-expiratory left ventricular end-diastolic pressure (LVEDP–end Exp–end Exp). Methods We prospectively performed left and right cardiac catheterization on 61 patients referred for evaluation of PH and compared the LVEDP–end Exp to end-expiration to the ( a ) PCWP–end Exp and ( b ) PCWP-digital. Results The PCWP–end Exp was a more reliable reflection of LVEDP–end Exp (mean 13.2 mm Hg vs 12.4 mm Hg; P , nonsignificant) than PCWP-digital (mean 8.0 mm Hg vs 12.4 mm Hg, P < .05). Bland-Altman analysis of PCWP-digital and LVEDP–end Exp revealed a mean bias of −4.4 mm Hg with 95% limits of agreement of −11.3 to 2.5 mm Hg. Bland-Altman analysis of PCWP–end Exp and LVEDP–end Exp revealed a mean bias of 0.9 mm Hg with 95% limits of agreement of −5.2 to 6.9 mm Hg. If PCWP-digital were used to define LVEDP–end Exp, 14 (27%) of 52 patients would have been misclassified as having PAH rather than PH-HFpEF. Patients with obesity and hypoxia were particularly more likely to be misclassified as PAH instead of PH-HFpEF if PCWP-digital was used to define LVEDP–end Exp (odds ratio 8.1, 95% CI 1.644-40.04, P = .01). Conclusions The common practice of using PCWP-digital instead of PCWP–end Exp results in a significant underestimation of LVEDP–end Exp. In our study, this translated to nearly 30% of patients being misclassified as having PAH rather than PH from HFpEF.
Pulmonary hypertension (PH) is characterised by a progressive decline in cardiac output (CO) and right heart failure. NICOM® (noninvasive cardiac output monitor) is a bioreactance-based technology ...that has been broadly validated, but its specific application in right heart failure and PH is unknown. Cardiac catheterisation was performed in 50 consecutive patients with PH. CO measurements were performed using three different methods (thermodilution, Fick and NICOM) at baseline and after vasodilator challenge. We compared the precision (coefficient of variation) and accuracy of NICOM compared to thermodilution and Fick. The mean CO (L·min(-1)) at baseline as measured by the three methods was 4.73±1.15 (NICOM), 5.69±1.74 (thermodilution) and 4.84±1.39 (Fick). CO measured by NICOM was more precise than by thermodilution (3.5±0.3% versus 9.6±6.1%, p<0.001). Bland-Altman analyses comparing NICOM to thermodilution and Fick revealed bias and 95% limits of agreement that were comparable to those comparing Fick to thermodilution. All three CO methods detected an increase in CO in response to vasodilator challenge. CO measured via NICOM is precise and reliably measures CO at rest and changes in CO with vasodilator challenge in patients with PH. NICOM may allow for the noninvasive haemodynamic assessment of patients with PH and their response to therapy.
Early right-sided heart failure (RHF) after left ventricular assist device (LVAD) implantation is associated with increased mortality, but little is known about patients who develop late RHF (LRHF). ...We evaluated the incidence, risk factors, and clinical impact of LRHF in patients supported by axial-flow LVADs.
Data were analyzed from 537 patients enrolled in the HeartMate II (HM II; Thoratec/St. Jude) destination therapy clinical trial. LRHF was defined as the development of clinical RHF accompanied by the need for inotropic support occurring more than 30 days after discharge from the index LVAD implant hospitalization. Clinical variables, quality of life, rehospitalizations, and survival were compared between patients with and without LRHF.
LRHF developed in 41 patients (8%), with a median time to LRHF of 480 days. A higher preoperative blood urea nitrogen and increased central venous pressure-to-pulmonary capillary wedge pressure ratio were independent predictors of LRHF. The Michigan and HMII RHF risk scores were both associated with an increased likelihood of LRHF (p < 0.05). Patients with LRHF had worse quality of life according to the Kansas City Cardiomyopathy Questionnaire (61 ± 26 vs 70 ± 21; p < 0.05), poorer functional capacity by 6-minute walk distance (275 ± 189 m vs 312 ± 216 m; p < 0.05), and more rehospitalizations (6 vs 3; p < 0.001). LRHF was associated with decreased survival (p < 0.001).
LRHF is an important complication in patients with LVADs and is associated with worse quality of life, reduced functional capacity, more frequent hospitalizations, and worse survival compared with those without LRHF.
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