Ultrasound-measured quadriceps thickness and mortality in older patients with heart failure.

BACKGROUND: Ultrasound may be helpful for muscle mass assessment in heart failure (HF). We aimed to determine the feasibility and prognostic implications of ultrasound-measured quadriceps muscle thickness (QMT) in older patients with HF. METHODS: This was a post-hoc analysis of a multicenter prospective cohort study including patients hospitalized for HF aged ≥ 65 years. QMT at rest and during isometric contractions was measured in the supine position using ultrasound before discharge. RESULTS: The interobserver agreement for measuring QMT was excellent, with intraclass correlation coefficients (ICCs) of 0.979 (95% confidence interval [CI] 0.963-0.988) at rest and 0.997 (95% CI 0.994-0.998) during isometric contraction. The intra-observer reproducibility was also excellent (ICC >0.92). Of the 595 patients (median age: 81 years, 56% male), median QMT at rest and during contraction were 18.9 mm and 24.9 mm, respectively. The patients were grouped according to sex-specific tertiles of height-adjusted QMT. During the median follow-up of 735 days, 157 deaths occurred, and Kaplan-Meier curve analysis showed that the lowest tertile of the height-adjusted QMT was associated with higher mortality. Cox proportional hazard analysis revealed that thinner height-adjusted QMT was independently associated with higher mortality, even after adjusting for conventional risk factors (per 1 mm/m increase: hazard ratio [HR] 0.94, 95% CI 0.89-0.99, P=0.030 [at rest] and HR 0.94, 95% CI 0.90-0.99, P=0.015 [during isometric contraction]). CONCLUSIONS: Ultrasound-measured QMT in older patients with HF is feasible, and thinner height-adjusted QMT at rest and during isometric contraction was independently associated with higher mortality.

Correlates of sleep-disordered breathing and Cheyne-Stokes respiration in patients with atrial fibrillation who have undergone pulmonary vein isolation.

Sleep disordered breathing (SDB) is a common comorbidity in patients with atrial fibrillation (AF). Patients undergoing pulmonary vein isolation (PVI) for AF have a high prevalence of SDB. In previous studies, some patients with AF had Cheyne-Stokes respiration (CSR). The aim of the present study was to assess the prevalence of SDB and the correlates of SDB severity and CSR in AF patients who have undergone PVI. The study was conducted using a single-center observational design. All participants underwent a home sleep apnea test (ApneaLink Air, ResMed, Australia), which could determine the severity of SDB as assessed by the apnea-hypopnea index (AHI) and the percentage of CSR (%CSR) pattern. 139 AF patients who underwent PVI were included in the study. Overall, 38 (27.3%) patients had no SDB (AHI < 5), 53 (38.1%) had mild SDB (5 ≤ AHI < 15), 33 (23.7%) had moderate SDB (15 ≤ AHI < 30), and 15 (10.8%) had severe SDB (AHI ≥ 30). Correlates of the increased AHI included male sex (ß = 0.23, p = 0.004), age (ß = 0.19, p = 0.020), high body mass index (ß = 0.31, p < 0.001), and ß blockers usage (ß = 0.18, p = 0.024). Conversely, correlates with the %CSR rate included male sex (ß = 0.18, p = 0.020), age (ß = 0.19, p = 0.015), non-paroxysmal AF (ß = 0.22, p = 0.008), and high glycohemoglobin A1c (ß = 0.36, p < 0.001) and N-terminal pro-brain natriuretic peptide (ß = 0.24, p = 0.005) levels. SDB is prevalent in patients with AF who have undergone PVI; predisposing factors for SDB include male sex, older age, and obesity. CSR occurs in patients with AF who have undergone PVI; predisposing factors for CSR include male sex, older age, high left ventricular filling pressure, and abnormal blood glucose level.

Multicenter validation study for automated left ventricular ejection fraction assessment using a handheld ultrasound with artificial intelligence.

We sought to validate the ability of a novel handheld ultrasound device with an artificial intelligence program (AI-POCUS) that automatically assesses left ventricular ejection fraction (LVEF). AI-POCUS was used to prospectively scan 200 patients in two Japanese hospitals. Automatic LVEF by AI-POCUS was compared to the standard biplane disk method using high-end ultrasound machines. After excluding 18 patients due to infeasible images for AI-POCUS, 182 patients (63 ± 15 years old, 21% female) were analyzed. The intraclass correlation coefficient (ICC) between the LVEF by AI-POCUS and the standard methods was good (0.81, p < 0.001) without clinically meaningful systematic bias (mean bias -1.5%, p = 0.008, limits of agreement ± 15.0%). Reduced LVEF < 50% was detected with a sensitivity of 85% (95% confidence interval 76%-91%) and specificity of 81% (71%-89%). Although the correlations between LV volumes by standard-echo and those by AI-POCUS were good (ICC > 0.80), AI-POCUS tended to underestimate LV volumes for larger LV (overall bias 42.1 mL for end-diastolic volume). These trends were mitigated with a newer version of the software tuned using increased data involving larger LVs, showing similar correlations (ICC > 0.85). In this real-world multicenter study, AI-POCUS showed accurate LVEF assessment, but careful attention might be necessary for volume assessment. The newer version, trained with larger and more heterogeneous data, demonstrated improved performance, underscoring the importance of big data accumulation in the field.

Feasibility of self-measurement telemonitoring using a handheld heart sound recorder in patients with heart failure - SELPH multicenter pilot study.

BACKGROUND: Multi-parametric assessment, including heart sounds in addition to conventional parameters, may enhance the efficacy of noninvasive telemonitoring for heart failure (HF). We sought to assess the feasibility of self-telemonitoring with multiple devices including a handheld heart sound recorder and its association with clinical events in patients with HF. METHODS: Ambulatory HF patients recorded their own heart sounds, mono­lead electrocardiograms, oxygen saturation, body weight, and vital signs using multiple devices every morning for six months. RESULTS: In the 77 patients enrolled (63 ±â€¯13 years old, 84 % male), daily measurements were feasible with a self-measurement rate of >70 % of days in 75 % of patients. Younger age and higher Minnesota Living with Heart Failure Questionnaire scores were independently associated with lower adherence (p = 0.002 and 0.027, respectively). A usability questionnaire showed that 87 % of patients felt self-telemonitoring was helpful, and 96 % could use the devices without routine cohabitant support. Six patients experienced ten HF events of re-hospitalization and/or unplanned hospital visits due to HF. In patients who experienced HF events, a significant increase in heart rate and diastolic blood pressure and a decrease in the time interval from Q wave onset to the second heart sound were observed 7 days before the events compared with those without HF events. CONCLUSIONS: Self-telemonitoring with multiple devices including a handheld heart sound recorder was feasible even in elderly patients with HF. This intervention may confer a sense of relief to patients and enable monitoring of physiological parameters that could be valuable in detecting the deterioration of HF.

Impact of sleep-disordered breathing on overnight changes in arterial stiffness in patients with acute heart failure.

Overnight increases in arterial stiffness associated with sleep-disordered breathing may adversely affect patients with acute heart failure. Thus, we investigated overnight changes in arterial stiffness and their association with sleep-disordered breathing in patients hospitalized for acute heart failure. Consecutive patients with acute heart failure were enrolled. All participants underwent overnight full polysomnography following the initial improvement of acute signs and symptoms of acute heart failure. The arterial stiffness parameter, cardio-ankle vascular index (CAVI), was assessed before and after polysomnography. Overall, 60 patients (86.7% men) were analyzed. CAVI significantly increased overnight (from 8.4 ± 1.6 at night to 9.1 ± 1.7 in the morning, P < 0.001) in addition to systolic and diastolic blood pressure (from 114.1 mmHg to 121.6 mmHg, P < 0.001; and from 70.1 mmHg to 78.2 mmHg, P < 0.001, respectively). Overnight increase in CAVI (ΔCAVI ≥ 0) was observed in 42 patients (70%). The ΔCAVI ≥ 0 group was likely to have moderate-to-severe sleep-disordered breathing (i.e., apnea-hypopnea index ≥15, 55.6% vs 80.9%, P = 0.047) and greater obstructive respiratory events (29.4% vs 58.5%, P = 0.041). In multivariable analysis, moderate-to-severe sleep-disordered breathing and greater obstructive respiratory events were independently correlated with an overnight increase in CAVI (P = 0.033 and P = 0.042, respectively). In patients hospitalized for acute heart failure, arterial stiffness, as assessed by CAVI, significantly increased overnight. Moderate-to-severe sleep-disordered breathing and obstructive respiratory events may play an important role in the overnight increase in cardio-ankle vascular index.

A Case Report of Mixed-type Dyspnoea Diagnosed via Non-invasive and Invasive Cardiopulmonary Exercise Tests.

A gas exchange analysis with the cardiopulmonary exercise test is effective in discriminating non-cardiogenic components of limited exercise tolerance and is important for use in combination with the diastolic stress test. An 80-year-old woman with progressive exertional dyspnoea, hypertension, and untreated bronchial asthma was diagnosed with heart failure with a preserved ejection fraction by invasive testing. Diuretics were initiated, which resulted in partial symptom improvement. A subsequent non-invasive test revealed a reduced breathing reserve, suggesting exertional dyspnoea complications linked to lung disease. Bronchodilators were administered, which further improved the symptoms.

Diurnal Variations in Serum Uric Acid, Xanthine, and Xanthine Oxidoreductase Activity in Male Patients with Coronary Artery Disease.

Hyperuricemia is influenced by diet and can cause gout. Whether it is a potential risk factor for cardiovascular disease (CVD) remains controversial, and the mechanism is unclear. Similar to CVDs, gout attacks occur more frequently in the morning and at night. A possible reason for this is the diurnal variation in uric acid (UA), However, scientific data regarding this variation in patients with CVD are not available. Thus, we aimed to investigate diurnal variations in serum levels of UA and plasma levels of xanthine, hypoxanthine, and xanthine oxidoreductase (XOR) activity, which were measured at 18:00, 6:00, and 12:00 in male patients with coronary artery disease. Thirty eligible patients participated in the study. UA and xanthine levels significantly increased from 18:00 to 6:00 but significantly decreased from 6:00 to 12:00. By contrast, XOR activity significantly increased both from 18:00 to 6:00 and 6:00 to 12:00. Furthermore, the rates of increase in UA and xanthine levels from night to morning were significantly and positively correlated. In conclusion, UA and xanthine showed similar diurnal variations, whereas XOR activity showed different diurnal variations. The morning UA surge could be due to UA production. The mechanism involved XOR activity, but other factors were also considered.

Overnight changes in uric acid, xanthine oxidoreductase and oxidative stress levels and their relationships with sleep-disordered breathing in patients with coronary artery disease.

Serum uric acid (UA) level is associated with the high cumulative incidence or prevalence of coronary artery disease (CAD), and hyperuricemia is considered as an independent risk marker for CAD. Sleep-disordered breathing (SDB) is also associated with an increased risk of CAD. Several studies have shown that SDB is associated with hyperuricemia, but the mechanisms are unclear. We measured serum levels of UA and xanthine oxidoreductase (XOR) activity and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), all of which were assessed at 6 p.m. and the following 6 a.m. in males with CAD. In addition, nocturnal pulse oximetry was performed for the night. Overall 32 eligible patients with CAD were enrolled. Serum UA levels significantly increased overnight. (5.32 ± 0.98 mg/dl to 5.46 ± 1.02 mg/dl, p < 0.001) Moreover, XOR activity and urinary 8-OHdG levels significantly increased from 6 p.m. to 6 a.m. Furthermore, 3% Oxygen desaturation index (ODI) was correlated with the overnight changes in XOR activity (r = 0.36, P = 0.047) and urinary 8-OHdG levels (r = 0.41, P = 0.02). In addition, 3%ODI was independently correlated with the changes in XOR activity (correlation coefficient, 0.36; P = 0.047) and 8-OHdG (partial correlation coefficient, 0.63; P = 0.004) in multivariable analyses. SDB severity was associated with the overnight changes in XOR activity and urinary 8-OHdG, suggesting that SDB may be associated with oxidative stress via UA production. This trial is registered at University Hospital Medical Information Network (UMIN), number: UMIN000021624.

A case of adult patent ductus arteriosus-associated infective endarteritis who was successfully treated with only antibiotics.

Patent ductus arteriosus-associated infective endarteritis (PDA-IE) is an extremely rare complication of PDA in recent years. In this report, we describe a case of PDA-IE complicated by septic pulmonary embolism who was successfully treated with only antibiotics.

Prognostic Value of Cheyne-Stokes Respiration and Nutritional Status in Acute Decompensated Heart Failure.

Malnutrition frequently coexists with heart failure (HF), leading to series of negative consequences. Cheyne-Stokes respiration (CSR) is predominantly detected in patients with HF. However, the effect of CSR and malnutrition on the long-term prognosis of patients with acute decompensated HF (ADHF) remains unclear. We enrolled 162 patients with ADHF (median age, 62 years; 78.4% men). The presence of CSR was assessed using polysomnography and the controlling nutritional status score was assessed to evaluate the nutritional status. Patients were divided into four groups based on CSR and malnutrition. The primary outcome was all-cause mortality. In total, 44% of patients had CSR and 67% of patients had malnutrition. The all-cause mortality rate was 26 (16%) during the 35.9 months median follow-up period. CSR with malnutrition was associated with lower survival rates (log-rank p < 0.001). Age, hemoglobin, albumin, lymphocyte count, total cholesterol, triglyceride, low-density lipoprotein cholesterol, creatinine, estimated glomerular filtration rate, B-type natriuretic peptide, administration of loop diuretics, apnea-hypopnea index and central apnea-hypopnea index were significantly different among all groups (p < 0.05). CSR with malnutrition was independently associated with all-cause mortality. In conclusion, CSR with malnutrition is associated with a high risk of all-cause mortality in patients with ADHF.

Effects of NP-1815-PX, a P2X4 Receptor Antagonist, on Contractions in Guinea Pig Tracheal and Bronchial Smooth Muscles.

Administration of a P2X4 receptor antagonist to asthma model mice improved asthma symptoms, suggesting that P2X4 receptor antagonists may be new therapeutics for asthma. However, the effects of these antagonists on tracheal/bronchial smooth muscle (TSM and BSM) have not been investigated. This study examined the effects of NP-1815-PX, a selective P2X4 receptor antagonist, on guinea pig TSM and BSM contractions. In epithelium-intact TSM, NP-1815-PX (10-5 M) strongly suppressed ATP-induced contractions. ATP-induced contractions were strongly suppressed by indomethacin (3 × 10-6 M) and ONO-8130 (a prostanoid EP1 receptor antagonist, 10-7 M). ATP-induced contractions were partially suppressed by SQ 29,548 (a prostanoid TP receptor antagonist, 3 × 10-7 M), although the difference was not significant. In contrast, ATP-induced contractions were not affected by AL 8810 (a prostanoid FP receptor antagonist, 10-5 M) or L-798,106 (a prostanoid EP3 receptor antagonist, 10-8 M). NP-1815-PX (10-5-10-4 M) strongly suppressed U46619 (a TP receptor agonist)- and prostaglandin F2α (PGF2α)-induced epithelium-denuded TSM and BSM contractions, which were largely inhibited by SQ 29,548. Additionally, NP-1815-PX (10-5-10-4 M) strongly suppressed the U46619-induced increase in intracellular Ca2+ concentrations in human TP receptor-expressing cells. However, NP-1815-PX (10-4 M) did not substantially inhibit the TSM/BSM contractions induced by carbachol, histamine, neurokinin A, or 50 mM KCl. These findings indicate that NP-1815-PX inhibits guinea pig TSM and BSM contractions mediated through the TP receptor, in addition to the P2X4 receptor, whose stimulation mainly induces EP1 receptor-related mechanisms. Thus, these findings support the usefulness of NP-1815-PX as a therapeutic drug for asthma.

Docosahexaenoic acid and eicosapentaenoic acid strongly inhibit prostanoid TP receptor-dependent contractions of guinea pig gastric fundus smooth muscle.

The inhibitory effects of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and linoleic acid (LA) on the contractions induced by five prostanoids and U46619 (a TP receptor agonist) were examined in guinea pig gastric fundus smooth muscle (GFSM). Tension changes were isometrically measured, and the mRNA expression of prostanoid receptors was measured by RT-qPCR. DHA and EPA significantly inhibited contractions induced by the prostanoids and U46619, whereas LA inhibited those induced by prostaglandin D2 and U46619. The mRNA expression levels of the prostanoid receptors were TP ≈ EP3  >> FP > EP1 . The inhibition by DHA, EPA, and LA was positively correlated with that by SQ 29,548 (a TP receptor antagonist) but not with that by L-798,106 (an EP3 receptor antagonist). DHA and EPA suppressed high KCl-induced contractions by 35% and 25%, respectively, and the contractions induced by the prostanoids and U46619 were suppressed by verapamil, a voltage-dependent Ca2+ channel (VDCC) inhibitor, by 40%-85%. Although LA did not suppress high KCl-induced contractions, it suppressed U46619-induced contractions in the presence of verapamil. However, LA did not show significant inhibitory effects on U46619-induced Ca2+ increases in TP receptor-expressing cells. In contrast, LA inhibited U46619-induced contractions in the presence of verapamil, which was also suppressed by SKF-96365 (a store-operated Ca2+ channel [SOCC] inhibitor). These findings suggest that the TP receptor and VDCC are targets of DHA and EPA to inhibit prostanoid-induced contractions of guinea pig GFSM, and SOCCs play a significant role in LA-induced inhibition of U46619-induced contractions.

Docosahexaenoic Acid Selectively Suppresses U46619- and PGF2α-Induced Contractions in Guinea Pig Tracheal Smooth Muscles.

We investigated the potential inhibitory effects of docosahexaenoic acid (DHA) on the contractions of guinea pig tracheal smooth muscles in response to U46619 (a thromboxane A2 (TXA2) mimetic) and prostaglandin F2α (PGF2α) to examine whether this n-3 polyunsaturated fatty acid suppresses prostanoid-induced tracheal contractions. DHA (3 × 10-5 M) significantly suppressed tracheal contractions elicited by lower concentrations of U46619 (10-8 M) and PGF2α (5 × 10-7 M) (vs. control), although it did not suppress the contractions induced by higher concentrations (U46619: 10-7 M; PGF2α: 10-5 M). Supporting these findings, DHA (4 × 10-5 M/6 × 10-5 M) shifted the concentration-response curves for U46619 (10-9-10-6 M) and PGF2α (10-8-10-5 M) to the right. However, the slope of the regression line in the Schild plot of DHA vs. U46619/PGF2α was larger than unity. The tracheal contractions induced by U46619 (10-8 M) and PGF2α (5 × 10-7 M) were significantly suppressed by the prostanoid TP receptor antagonist SQ 29,548 (10-6 M) (vs. ethanol-treated). In contrast, DHA (4 × 10-5 M) did not show significant inhibitory effects on the contractions induced by acetylcholine (10-8-10-4 M), histamine (10-8-10-4 M), and leukotriene D4 (10-11-10-7 M) (vs. ethanol-treated). These findings indicate that DHA selectively suppresses tracheal contractions induced by U46619 and PGF2α. Therefore, DHA may be a useful therapeutic agent against asthma associated with tracheal/bronchial hyper-constriction caused by prostanoids including TXA2 and PGF2α.

Prognostic effect of sleep-disordered breathing on hospitalized patients following acute heart failure.

BACKGROUND: Identifying patients at risk for poor clinical outcomes following acute heart failure (AHF) is essential. However, data regarding the prognostic effect of sleep-disordered breathing (SDB) and treatment with positive airway pressure (PAP) on clinical outcomes of hospitalized patients following AHF is lacking. OBJECTIVES: This study investigated the prognostic effect of SDB, PAP treatment, and compliance with PAP treatment on patient clinical outcomes. Polysomnography was performed in hospitalized patients whose left ventricular ejection fraction was < 50%. Patients were divided into groups based on whether SDB was defined as an apnea-hypopnea index ≥ 15 and if they had received PAP treatment. Furthermore, patients with SDB and PAP were subdivided into more and less compliant groups. We assessed the incidences of deaths and rehospitalizations due to heart failure. RESULTS: Overall, 241 patients were enrolled; 73% had SDB and 29% were initiated on PAP treatment. At a median follow-up of 1.7 years, 74 clinical events (32 deaths, 42 rehospitalizations) occurred. In the multivariable analysis, compared with the non-SDB group, SDB without PAP treatment was associated with an increased risk of clinical outcomes (hazard ratio [HR] 1.79, P = 0.049), whereas SDB with PAP treatment was not (HR 0.78, P = 0.582). Among patients with PAP treatment, a more compliant group was also inversely associated with clinical events (HR 0.11, P = 0.012). CONCLUSIONS: In hospitalized patients with AHF, untreated SDB was associated with worse clinical outcomes that might be reversible by PAP treatment. However, this potential may be suppressed in less compliant patients.

Atypical Shone's Complex Diagnosed at 70 Years Old: Presenting with Double-orifice Mitral Valve, Bicuspid Aortic Valve, and Aortic Coarctation.

Atypical Shone's complex is a rare congenital anomaly involving a left-sided obstructive lesion of two or three cardiovascular levels. A 70-year-old man with dyspnea on exertion was diagnosed with severe aortic stenosis (AS) with a bicuspid valve, complicated by severe aortic coarctation (CoA) and a double-orifice mitral valve. He underwent surgery for AS and CoA in one session. It is important to search for complicated malformations, even in cases of bicuspid aortic valve found in old age.

Effectiveness of real-time tele-ultrasound for echocardiography in resource-limited medical teams.

BACKGROUND: Echocardiography is a first-line tool for the screening of patients with cardiac dysfunction. However, the mastery of echocardiography requires significant training, and not all medical teams involve an echocardiography specialist. Telemedicine approaches can potentially improve the quality of echocardiography in resource-limited situations. METHODS: We used a novel tablet-based hand-held ultrasound device that enables tele-ultrasound- a real-time video telecommunication with remote control for ultrasound images. A trainee scanned patients with various cardiovascular diseases and interpreted the images. Subsequently, the same trainee re-scanned the same patients and re-interpreted the same images using tele-ultrasound with an echocardiography specialist. An examination on the same patients by a blinded specialist was considered the gold standard. RESULTS: We included 31 patients (median 77 [interquartile range 68-84] years old, 42% women). Mean absolute errors in left ventricular (LV) end-diastolic and end-systolic diameters, visual LV ejection fraction, and tricuspid annular plane systolic excursion decreased significantly after tele-ultrasound advice (5.9 mm, 5.8 mm, 8.6%, and 4.5 to 1.6 mm, 2.8 mm, 0.7%, and 1.8 mm, respectively, all p < 0.001), and intra-class correlation coefficients improved (0.76, 0.84, 0.68, and 0.44 to 0.96, 0.93, 0.99, and 0.90, respectively). Notably, with tele-advice, the trainee's examination showed perfect agreement with that of the specialist in classifying LV ejection fraction (> 50%, 50-35%, or > 35%) and identifying significant valvular heart diseases. CONCLUSION: Real-time tele-ultrasound improved a trainee's echocardiography results to those of a specialist-level examination. This approach might be helpful in resource-limited medical teams where echocardiographic specialists are not readily available.

Temporal changes of cardiac acoustic biomarkers and cardiac function in acute decompensated heart failure.

AIMS: Relationships between cardiac acoustic biomarkers (CABs) measured by acoustic cardiography and clinical outcomes have been reported in heart failure (HF) patients. However, no studies have investigated the temporal change of CABs and the corresponding changes in HF status. The purpose of this study was to assess whether the temporal changes of CABs in patients with acute decompensated heart failure (ADHF) reflect changes in cardiac function and status. METHODS AND RESULTS: Sixty ADHF patients were enrolled prospectively. CABs and echocardiography data were collected at admission, before discharge, and at the first clinic visit. CABs included electromechanical activation time (EMAT); the time interval from Q wave onset on electrocardiography to the first heart sound (S1), QoS2; the time interval from Q wave onset on electrocardiography to the second heart sound (S2); and third heart sound (S3) and fourth heart sound (S4) intensities, defined as the peak-to-peak amplitudes of S3 and S4. EMATc (EMAT/RR) (P = 0.001), S3 intensity (P < 0.001), and S4 intensity (P < 0.001) were significantly decreased, and QoS2 (P = 0.005) was significantly increased from admission to discharge. The change in S3 intensity was significantly correlated with that of E/A (ρ = 0.571, P < 0.001), and the extended QoS2 was also significantly correlated with the increase in the stroke volume index (ρ = 0.383, P = 0.004). CONCLUSIONS: Some CABs in ADHF patients changed significantly in the normal direction throughout the treatment course and could be useful biomarkers in ADHF management.

Prognostic effects of arterial carbon dioxide levels in patients hospitalized into the cardiac intensive care unit for acute heart failure.

AIMS: Although both hypercapnia and hypocapnia are common in acute heart failure (AHF) patients, routine assessment of arterial blood gas is not recommended. Additionally, no association between hypercapnia and increased mortality has been found, and the prognostic value of hypocapnia in AHF patients remains to be elucidated. In this observational study, we aimed to investigate the relationship between partial pressure of arterial carbon dioxide (PaCO2), especially low PaCO2, and long-term mortality in AHF patients. METHODS AND RESULTS: Acute heart failure patients hospitalized in the cardiac intensive care unit of our institution between 2007 and 2011 were screened. All eligible patients were divided into two groups based on the inflection point (i.e. 31.0 mmHg) of the 3-knot cubic spline curve of the hazard ratio (HR), with a PaCO2 of 40 mmHg as a reference. The association between PaCO2 levels and all-cause mortality was assessed using Cox proportional hazards regression models. Among 435 patients with a median follow-up of 1.8 years, 115 (26.4%) died. Adjusted analysis with relevant variables as confounders indicated that PaCO2 <31 mmHg was significantly associated with increased all-cause mortality [HR 1.71, 95% confidence interval (CI) 1.05-2.79; P = 0.032]. When PaCO2 was considered as a continuous variable, the lower was the log-transformed PaCO2, the greater was the increased risk of mortality (HR 0.71, 95% CI 0.52-0.96; P = 0.024). CONCLUSIONS: In AHF patients, lower PaCO2 at admission was associated with increased long-term mortality risk.

Utility of cyclic variation of heart rate score as a screening tool for sleep-disordered breathing in patients with heart failure.

STUDY OBJECTIVES: Patients with sleep-disordered breathing have cyclic variation of heart rate (CVHR) in response to respiratory events. However, limited data are available regarding the utility of CVHR as a screening tool for sleep-disordered breathing in patients with mixed heart failure (HF) and those without HF. METHODS: We enrolled consecutive patients with and without HF who underwent full polysomnographies with simultaneous Holter electrocardiogram monitoring. We determined the temporal position of the individual dips comprising the CVHR score using time-domain methods. RESULTS: The data of 101 patients, including 70 with and 31 without HF, were analyzed. The CVHR score was significantly correlated with the apnea-hypopnea index (r = .667, P < .001) and limits of agreement between the apnea-hypopnea index and CVHR score were -21.8 to 35.2. The receiver operating characteristic analysis demonstrated that the CVHR score (best cut-off of 23.5 events/h) identified severe sleep-disordered breathing with a sensitivity of 83.3%, specificity of 79.5%, and the area under the curve of 0.856. In addition, there was no interaction between the presence or absence of HF and the apnea-hypopnea index-CVHR score relationship (P = .323). CONCLUSIONS: The CVHR score, determined by Holter electrocardiogram monitoring, is a useful tool for evaluating sleep-disordered breathing even in patients with mixed HF and patients without HF. CITATION: Yatsu S, Kasai T, Naito R, et al. Utility of cyclic variation of heart rate score as a screening tool for sleep-disordered breathing in patients with heart failure. J Clin Sleep Med. 2021;17(11):2187-2196.