Noninvasive determination of pulmonary artery wedge pressure in patients with chronic heart failure

Advances and Challenges in Biomarkers Use for Coronary Microvascular Dysfunction: From Bench to Clinical Practice

Coronary microvascular dysfunction (CMD) is related to a broad variety of clinical scenarios in which cardiac microvasculature is morphologically and functionally affected, and it is associated with impaired responses to vasoactive stimuli. Although the prevalence of CMD involves about half of all patients with chronic coronary syndromes and more than 20% of those with acute coronary syndrome, the diagnosis of CMD is often missed, leading to the underestimation of its clinical importance. The established and validated techniques for the measurement of coronary microvascular function are invasive and expensive. An ideal method to assess endothelial dysfunction should be accurate, non-invasive, cost-effective and accessible. There are varieties of biomarkers available, potentially involved in microvascular disease, but none have been extensively validated in this heterogeneous clinical population. The investigation of potential biomarkers linked to microvascular dysfunction might improve the assessment of the diagnosis, risk stratification, disease progression and therapy response. This review article offers an update about traditional and novel potential biomarkers linked to CMD.

Valsalva-derived Measures and Phenylephrine Test in Patients With Heart Failure With Reduced Ejection Fraction Receiving Comprehensive Neurohormonal Blockade Drug Therapy: A 5-year Event-free Survival Analysis

BACKGROUND

To assess the relationships between Valsalva- and phenylephrine test-derived measures and outcome in patients with heart failure with reduced ejection fraction (HFrEF) receiving comprehensive neurohormonal blockade pharmacotherapy.

METHODS AND RESULTS

Data from 56 patients with HFrEF (mean left ventricle ejection fraction of 32 ± 6%) subjected to Valsalva and phenylephrine tests were analyzed retrospectively. Baroreflex-related (Valsalva-ratio and blood pressure-RR interval slope from phase IV) and non-baroreflex-related measures (systolic blood pressure rise in phase IV [ΔSBP_{PHASE_IV}], and pulse amplitude ratio [PAR]) were calculated from Valsalva. Short-term outcomes (HF-related hospitalization, implantable cardioverter-defibrillator shock or all-cause death within 24 months from examination) and long-term outcomes (implantable cardioverter-defibrillator shock or all-cause death within 60 months) were analyzed. The end point occurred in 16 and 18 patients, for the short- and long-term outcomes, respectively. A low ΔSBP_{PHASE_IV} identified patients at risk in the long term, as evidenced by a low vs high ΔSBP_{PHASE_IV} comparison (square-wave response patients assigned to low ΔSBP_{PHASE_IV} group, P = .002), and Cox model (hazard ratio 0.91, 95% confidence interval 0.86-0.96, P < .001), and tended to identify patients at risk in the short term outcome (hazard ratio 0.95, 95% confidence interval 0.91-1.00, P = .055). There was a tendency toward a higher event-free survival in the low PAR group (low vs high PAR; hazard ratio 0.44, 95% CI 0.17-1.18, P = .104).

CONCLUSIONS

Non-baroreflex-related measures obtained from Valsalva-namely, ΔSBP_{PHASE_IV} and PAR-might carry prognostic value in patients with HFrEF receiving neurohormonal blockade pharmacotherapy.

Usefulness of Noninvasively Measured Pulse Amplitude Changes During the Valsalva Maneuver to Identify Hospitalized Heart Failure Patients at Risk of 30-Day Heart Failure Events (from the PRESSURE-HF Study)

The pulse amplitude ratio (PAR), the ratio of pulse pressure at the end of the Valsalva maneuver to before the onset, correlates with cardiac filling pressure. We have developed a handheld device that uses finger photoplethysmography to measure PAR and estimate left ventricular end diastolic pressure (LVEDP). Patients hospitalized with heart failure (HF) performed three 10-second trials of a standardized Valsalva maneuver (at 20 mm Hg measured via pressure transducer), while photoplethysmography waveforms were recorded, at admission and discharge. Combined primary outcome was 30-day HF hospitalization, intravenous diuresis, or death. Fifty-two subjects had discharge PAR testing; 12 met the primary outcome. Median PAR on admission was 0.55 (interquartile range: 0.40 to 0.70, n = 48) and on discharge was 0.50 (interquartile range: 0.36 to 0.69). Mean PAR-estimated LVEDP was significantly higher in subjects that had an event (20.2 vs 16.9 mm Hg, p = 0.043). Subjects with PAR-estimated LVEDP >19.5 mm Hg had an event rate hazard ratio of 4.57 (95% confidence interval 1.37, 15.19, p = 0.013) compared with patients with LVEDP 19.5 mm Hg or below, with significantly lower 30-day event-free survival (log-rank p = 0.006). In conclusion, noninvasively estimated LVEDP using the pulse amplitude response to a Valsalva maneuver in patients hospitalized for HF changes with diuresis and identifies patients at high risk for 30-day HF events. Detection of elevated filling pressures before hospital discharge may be useful in guiding HF management to reduce HF events.

The Role of the Clinical Examination in Patients With Heart Failure

Despite advances in biomarkers and technology, the clinical examination (i.e., a history and physical examination) remains central in the management of patients with heart failure. Specifically, the clinical examination allows noninvasive assessment of the patient's underlying hemodynamic state, based on whether the patient has elevated ventricular filling pressures and/or an inadequate cardiac index. Such assessments provide important prognostic information and help guide therapeutic decision-making. Herein, the authors critically assess the utility of the clinical examination for these purposes and provide practical tips we have gleaned from our practice in the field of advanced heart failure. The authors note that the ability to assess for congestion is superior to that for inadequate perfusion. Furthermore, in current practice, elevated left ventricular filling pressures are inferred by findings related to an elevated right atrial pressure. They discuss an emerging classification system from the clinical examination that categorizes patients based on whether elevation of ventricular filling pressures occurs on the right side, left side, or both sides.

Impact of overweight on left ventricular function in type 2 diabetes mellitus

Background

Coexistence of left ventricular (LV) longitudinal myocardial systolic dysfunction with LV diastolic dysfunction could lead to heart failure with preserved ejection fraction (HFpEF). Diabetes mellitus (DM) is known as a significant factor associated with HFpEF. Although the mechanisms of DM-related LV myocardial injury are complex, it has been postulated that overweight contributes to the development of LV myocardial injury in type 2 diabetes mellitus (T2DM) patients. However, the precise impact of overweight on LV longitudinal myocardial systolic function in T2DM patients remains unclear.

Methods

We studied 145 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease. LV longitudinal myocardial systolic function was assessed by global longitudinal strain (GLS), which was defined as the average peak strain of 18-segments obtained from standard apical views. Overweight was defined as body mass index (BMI) ≥ 25 kg/m². Ninety age-, gender- and LVEF-matched healthy volunteers served as controls.

Results

GLS of overweight T2DM patients was significantly lower than that of non-overweight patients (17.9 ± 2.4% vs. 18.9 ± 2.6%, p < 0.05), whereas GLS of both overweight and non-overweight controls was similar (19.8 ± 1.3% vs. 20.4 ± 2.1%, p = 0.38). Furthermore, multiple regression analysis revealed that for T2DM patients, BMI was the independent determinant parameters for GLS as well as LV mass index.

Conclusions

Overweight has a greater effect on LV longitudinal myocardial systolic function in T2DM patients than on that in non-DM healthy subjects. Our finding further suggests that the strict control of overweight in T2DM patients may be associated with prevention of the development of HFpEF.

Usefulness of Pulse Amplitude Changes During the Valsalva Maneuver Measured Using Finger Photoplethysmography to Identify Elevated Pulmonary Capillary Wedge Pressure in Patients With Heart Failure

The pulse amplitude ratio, the ratio of pulse pressure at the end of a Valsalva maneuver to before the onset of Valsalva, correlates with filling pressure. This study aimed to noninvasively estimate cardiac filling pressure in patients with heart failure. We developed a noninvasive handheld device to measure pulse amplitude ratio using finger photoplethysmography. In 69 patients who underwent right heart catheterization, photoplethysmography waveforms were recorded during a standardized Valsalva maneuver, and in 60 of these patients, pulse amplitude ratio was able to be calculated. Pulse amplitude ratio correlated with pulmonary capillary wedge pressure (PCWP) (r = 0.58, p <0.0001), particularly among those subjects with reduced ejection fraction (r = 0.60, p = 0.002, n = 25). A multivariable linear regression model for PCWP including pulse amplitude ratio, age, body mass index, systolic blood pressure, diastolic blood pressure, and heart rate yielded an R² of 0.54. Difference in mean pulse amplitude ratio for subjects with a PCWP ≤15 mm Hg versus >15 mm Hg was statistically significant (p <0.0001, area under receiver operating characteristics curve 0.79 [0.66, 0.92]). Pulse amplitude ratio ≥0.55 predicted PCWP >15 mm Hg with 73% sensitivity and 77% specificity. Pulse amplitude ratio also increased by an average of 0.03 with a leg raise maneuver (p = 0.05, n = 36). In conclusion, we demonstrate that noninvasively measured response to the Valsalva maneuver in patients with HF can estimate PCWP and also detect changes within a single patient.

Repeated assessment of physical biomeasures or blood biomarkers for the definition of volume status and cardiac loading in LVSD

The application of biomarker technology can be usefully implemented in areas where current techniques are inadequate and where a clinical issue, which affects outcome, can be defined. The definition of the loading status of the heart where there is pre-existent impairment of contractile function is a key target. Heart failure is a complex clinical presentation with many varied etiologies, but at the essence of its successful management is the reliable definition of cardiac volume loading. Traditional and many current technological measures are applied to define this relationship, yet their accuracy and performance in individual patients is either basically inadequate or poorly understood and applied. There is a wide range of both physical measurements and blood biomarkers that can be considered to better define this key issue in patients with ventricular systolic impairment. Their performance is considered in detail in this review.

Finger photoplethysmography during the Valsalva maneuver reflects left ventricular filling pressure

It is often challenging to assess cardiac filling pressure clinically. An improved system for detecting or ruling out elevated cardiac filling pressure may help reduce hospitalizations for heart failure. The blood pressure response to the Valsalva maneuver reflects left heart filling pressure, but its underuse clinically may be due in part to lack of continuous blood pressure recording along with lack of standardization of expiratory effort. In this study, we tested whether Valsalva-induced changes in the pulse amplitude of finger photoplethysmography (PPG), a technology already widely available in medical settings, correlate with invasively measured left ventricular end-diastolic pressure (LVEDP). We tested 33 subjects before clinically scheduled cardiac catheterizations. A finger photoplethysmography waveform was recorded during a Valsalva effort of 20 mmHg expiratory pressure sustained for 10 s, an effort most patients can achieve. Pulse amplitude ratio (PAR) was calculated as the PPG waveform amplitude just before release of expiratory effort divided by the waveform amplitude at baseline. PAR was well correlated with LVEDP (r = 0.68; P < 0.0001). For identifying LVEDP > 15 mmHG, PAR > 0.4 was 85% sensitive [95% confidence interval (95CI): 54-97%] and 80% specific (95CI: 56-93%). In conclusion, finger PPG, a technology already ubiquitous in medical centers, may be useful for assessing clinically meaningful categories of left heart filling pressure, using simple analysis of the waveform after a Valsalva maneuver effort that most patients can achieve.

Left atrial longitudinal strain by speckle tracking echocardiography correlates well with left ventricular filling pressures in patients with heart failure

Background

The combination of early transmitral inflow velocity and mitral annular tissue Doppler imaging (E/Em ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However E/Em ratio has a significant gray zone and its accuracy in patients with heart failure is debated. Left atrial (LA) deformation analysis by speckle tracking echocardiography (STE) was recently proposed as an alternative approach to estimate LV filling pressures. This study aimed at exploring the correlation of LA longitudinal function by STE and Doppler measurements with direct measurements of LV filling pressures in patients with heart failure.

Methods

A total of 36 patients with advanced systolic heart failure (ejection fraction ≤35%), undergoing right heart catheterization, were studied. Simultaneously to pulmonary capillary wedge pressure (PCWP) determination, peak atrial longitudinal strain (PALS) and mean E/Em ratio were measured in all subjects by two independent operators. PALS values were obtained by averaging all segments (global PALS), and by separately averaging segments measured in the 4-chamber and 2-chamber views.

Results

Not significant correlation was found between mean E/Em ratio and PCWP (R = 0.15). A close negative correlation between global PALS and the PCWP was found (R = -0.81, p < 0.0001). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.93) and excellent sensitivity and specificity of 100% and 93%, respectively, to predict elevated filling pressure using a cutoff value less than 15.1%. Bland-Altman analysis confirmed this close agreement between PCWP estimated by global PALS and invasive PCWP (mean bias 0.1 ± 8.0 mmHg).

Conclusion

In a group of patients with advanced systolic heart failure, E/Em ratio correlated poorly with invasively obtained LV filling pressures. However, LA longitudinal deformation analysis by STE correlated well with PCWP, providing a better estimation of LV filling pressures in this particular clinical setting.

Clinical assessment of heart failure: utility of symptoms, signs, and daily weights

Heart failure is a clinical syndrome defined by the presence of characteristic signs and symptoms. History taking and physical examination have particular utility in assessing patients who have heart failure. In recent years the validity of conventional signs and symptoms of heart failure has been tested in large population studies and in clinical trials, providing an evidence basis for their utility in the clinical assessment of the patient who has known or suspected heart failure. There also has been progress in characterizing the process of acute decompensation from a previously chronic stable state. This article addresses the usefulness of signs and symptoms and daily weights in the assessment and management of patients who have heart failure.

The Valsalva maneuver: a bedside "biomarker" for heart failure

Accurate assessment of volume status remains an important clinical goal in the management of patients with heart failure. Although physical examination can provide clues to volume status, its sensitivity and reproducibility are limited. Other noninvasive methods, such as measurement of natriuretic peptides or the use of impedance cardiography, are not well validated. The cardiovascular response to the Valsalva maneuver had been proposed as a simple, inexpensive bedside test for estimating filling pressures in patients with heart failure. Our objective was to summarize and critically evaluate the evidence for the use of the Valsalva maneuver in evaluating volume status in patients with heart failure. Studies have demonstrated a significant correlation between the cardiovascular response to the Valsalva maneuver and invasively measured ventricular filling pressures in patients with clinical heart failure. Although often overlooked in clinical training and practice, the cardiovascular response to the Valsalva maneuver is a potentially useful, noninvasive means of evaluating filling pressures in patients with heart failure.

The prognostic value of the physical examination in patients with chronic heart failure

The importance placed on the physical examination in the assessment of patients with cardiovascular disorders appears to be declining, perhaps in part due to a paucity of data showing its value in the modern era. To determine whether the physical examination provides important prognostic information in patients with chronic heart failure, the authors performed a post-hoc analysis of 2479 participants from the Studies of Left Ventricular Dysfunction (SOLVD) treatment trial. The presence of elevated jugular venous pressure and a third heart sound at baseline were each associated with subsequent heart failure hospitalization, the composite end point of death or heart failure hospitalization, and pump-failure death, independently of many other markers of disease severity. The subgroup of patients with at least one of these two physical examination findings was at increased risk for all-cause mortality. The authors believe that additional studies assessing the prognostic value of the physical examination should be conducted and, if favorable, likely would lead to a renewed interest in the physical examination.