Prognostic impact of diastolic dysfunction in systolic heart failure-A cross-project analysis from the German Competence Network Heart Failure

Left ventricular diastolic dysfunction in patients with heart failure with mildly reduced ejection fraction

OBJECTIVE

This study investigates the prevalence and prognostic impact of diastolic dysfunction (DD) in patients hospitalized with heart failure (HF) with mildly reduced ejection fraction (HFmrEF) in sinus rhythm.

BACKGROUND

Data regarding the prognostic impact of DD in patients with HFmrEF is limited.

METHODS

From 2016 to 2022, all patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution. Patients with DD were compared to patients without (i.e., non-DD), further risk stratification was performed according to the severity of DD. The primary endpoint was all-cause mortality at 30 months (interquartile range (IQR) 15-61 months), key secondary endpoint was rehospitalization for worsening HF.

RESULTS

From a total of 1154 patients (median age 68 years, 68% males) hospitalized with HFmrEF, concomitant DD was present in 72% (grade I: 56%, grade II: 14%, grade III: 2%). Patients with DD were older (71 years vs. 65 years; p = 0.001) and presented with higher rates of cardiovascular comorbidities. The presence of DD was not associated with the risk of long-term all-cause mortality (adjusted HR = 0.815; 95% CI 0.612-1.085; p = 0.161) or HF-related rehospitalization (adjusted HR = 0.736; 95% CI 0.442-1.225; p = 0.238). Furthermore, the outcome did not differ in patients with more advanced stages of DD.

CONCLUSION

DD is commonly prevalent in patients with HFmrEF, but not associated with long-term prognosis.

Anthracyclines, Diastolic Dysfunction and the road to Heart Failure in Cancer survivors: An untold story

Many cardiovascular diseases are characterized by diastolic dysfunction, which associates with worse clinical outcomes like overall mortality and hospitalization for heart failure (HF). Diastolic dysfunction has also been suspected to represent an early manifestation of cardiotoxicity induced by cancer drugs, with most of the information deriving from patients treated with anthracyclines; however, the prognostic implications of diastolic dysfunction in the anthracycline-treated patient have remained poorly explored or neglected. Here the molecular, pathophysiologic and diagnostic aspects of anthracycline-related diastolic dysfunction are reviewed in the light of HF incidence and phenotype in cancer survivors. We describe that the trajectories of diastolic dysfunction toward HF are influenced by a constellation of patient- or treatment- related factors, such as comorbidities and exposure to other cardiotoxic drugs or treatments, but also by prospective novel opportunities to treat diastolic dysfunction. The importance of a research-oriented multidimensional approach to patient surveillance or treatment is discussed within the framework of what appears to be a distinct pathophysiologic entity that develops early during anthracycline treatment and gradually worsens over the years.

Prediction of recurrent heart failure hospitalizations and mortality using the echocardiographic Killip score

AIM

Examine the performance of a simple echocardiographic "Killip score" (eKillip) in predicting heart failure (HF) hospitalizations and mortality after index event of decompensated HF hospitalization.

METHODS

HF patients hospitalized at our facility between 03/2019-03/2021 who underwent an echocardiography during their index admission were included in this retrospective analysis. The cohort was divided into 4 classes of eKillip according to: stroke volume index (SVI) < 35ml/m2 > and E/E' ratio < 15 > . An eKillip Class I was defined as SVI ≥ 35ml/m2 and E/E' ≤ 15 and was used as reference.

RESULTS

Included 751 patients, median age 78.1 (IQR 69.3-86) years, 59% men, left ventricular ejection fraction 45 (IQR 30-60)%, brain natriuretic peptide levels 634 (IQR 331-1222)pg/ml. Compared with eKillip Class I, a graded increase in the combined endpoint of 30-day mortality and rehospitalizations rates was noted: (Class II: HR 1.77, CI 0.95-3.33, p = 0.07; Class III: HR 1.94, CI 1.05-3.6, p = 0.034; Class IV: HR 2.9, CI 1.64-5.13, p < 0.001 respectively), which overall persisted after correction for clinical (Class II: HR 1.682, CI 0.9-3.15, p = 0.105; Class III: HR 2.104, CI 1.13-3.9, p = 0.019; Class IV: HR 2.74, CI 1.54-4.85, p = 0.001 respectively) or echocardiographic parameters (Class II: HR 1.92, CI 1.02-3.63, p = 0.045; Class III: HR 1.54, CI 0.81-2.95, p = 0.189; Class IV: HR 2.04, CI 1.1-3.76, p = 0.023 respectively). Specifically, the eKillip Class IV group comprised one-third of the patient population and persistently showed increased risk of 30-day HF hospitalizations or mortality following multivariate analysis.

CONCLUSION

A simple echocardiographic score can assist identifying high-risk decompensated HF patients for recurrent hospitalizations and mortality.

Cardiac dysfunction and high-sensitive C-reactive protein are associated with troponin T elevation in ischemic stroke: insights from the SICFAIL study

BACKGROUND

Troponin elevation is common in ischemic stroke (IS) patients. The pathomechanisms involved are incompletely understood and comprise coronary and non-coronary causes, e.g. autonomic dysfunction. We investigated determinants of troponin elevation in acute IS patients including markers of autonomic dysfunction, assessed by heart rate variability (HRV) time domain variables.

METHODS

Data were collected within the Stroke Induced Cardiac FAILure (SICFAIL) cohort study. IS patients admitted to the Department of Neurology, Würzburg University Hospital, underwent baseline investigation including cardiac history, physical examination, echocardiography, and blood sampling. Four HRV time domain variables were calculated in patients undergoing electrocardiographic Holter monitoring. Multivariable logistic regression with corresponding odds ratios (OR) and 95% confidence intervals (CI) was used to investigate the determinants of high-sensitive troponin T (hs-TnT) levels ≥14 ng/L.

RESULTS

We report results from 543 IS patients recruited between 01/2014-02/2017. Of those, 203 (37%) had hs-TnT ≥14 ng/L, which was independently associated with older age (OR per year 1.05; 95% CI 1.02-1.08), male sex (OR 2.65; 95% CI 1.54-4.58), decreasing estimated glomerular filtration rate (OR per 10 mL/min/1.73 m² 0.71; 95% CI 0.61-0.84), systolic dysfunction (OR 2.79; 95% CI 1.22-6.37), diastolic dysfunction (OR 2.29; 95% CI 1.29-4.02), atrial fibrillation (OR 2.30; 95% CI 1.25-4.23), and increasing levels of C-reactive protein (OR 1.48 per log unit; 95% CI 1.22-1.79). We did not identify an independent association of troponin elevation with the investigated HRV variables.

CONCLUSION

Cardiac dysfunction and elevated C-reactive protein, but not a reduced HRV as surrogate of autonomic dysfunction, were associated with increased hs-TnT levels in IS patients independent of established cardiovascular risk factors. Registration-URL: https://www.drks.de/drks_web/; Unique identifier: DRKS00011615.

Impact of diastolic dysfunction on outcome in heart failure patients with mid-range or reduced ejection fraction

Aims

The role of diastolic dysfunction (DD) in prognostic evaluation in heart failure (HF) patients with impaired systolic function remains unclear. We investigated the impact of echocardiography‐defined DD on survival in HF patients with mid‐range (HFmrEF, EF 41–49%) and reduced ejection fraction (HFrEF, EF < 40%).

Methods and results

A total of 2018 consecutive hospitalized HF patients were retrospectively included and divided in two groups based on baseline EF: HFmrEF group (n = 951, aged 69 ± 13 years, 74.2% male) and HFrEF group (n = 1067, aged 68 ± 13 years, 76.3% male). Clinical data were collected and analysed. All patients completed ≥1 year clinical follow‐up. The primary endpoint was defined as all‐cause death (including heart transplantation) and cardiovascular (CV)‐related death. All‐cause mortality (30.8% vs. 24.9%, P = 0.003) and CV mortality (19.1% vs. 13.5%, P = 0.001) were significantly higher in the HFrEF group than the HFmrEF group during follow‐up [median 24 (13–36) months]. All‐cause mortality increased in proportion to DD severity (mild, moderate, and severe) in either HFmrEF (17.1%, 25.4%, and 37.0%, P < 0.001) or HFrEF (18.9%, 30.3%, and 39.2%, P < 0.001) patients. The risk of all‐cause mortality [hazard ratio (HR) = 1.347, P = 0.015] and CV mortality (HR = 1.508, P = 0.007) was significantly higher in HFrEF patients with severe DD compared with non‐severe DD after adjustment for identified clinical and echocardiographic covariates. For HFmrEF patients, severe DD was independently associated with increased all‐cause mortality (HR = 1.358, P = 0.046) but not with CV mortality (HR = 1.155, P = 0.469).

Conclusions

Echocardiography‐defined severe DD is independently associated with increased all‐cause mortality in patients with HFmrEF and HFrEF.

Prevalence and determinants of systolic and diastolic cardiac dysfunction and heart failure in acute ischemic stroke patients: The SICFAIL study

AIMS

Ischaemic stroke (IS) might induce alterations of cardiac function. Prospective data on frequency of cardiac dysfunction and heart failure (HF) after IS are lacking. We assessed prevalence and determinants of diastolic dysfunction (DD), systolic dysfunction (SD), and HF in patients with acute IS.

METHODS AND RESULTS

The Stroke-Induced Cardiac FAILure in mice and men (SICFAIL) study is a prospective, hospital-based cohort study. Patients with IS underwent a comprehensive assessment of cardiac function in the acute phase (median 4 days after IS) including clinical examination, standardized transthoracic echocardiography by expert sonographers, and determination of blood-based biomarkers. Information on demographics, lifestyle, risk factors, symptoms suggestive of HF, and medical history was collected by a standardized personal interview. Applying current guidelines, cardiac dysfunction was classified based on echocardiographic criteria into SD (left ventricular ejection fraction < 52% in men or <54% in women) and DD (≥3 signs of DD in patients without SD). Clinically overt HF was classified into HF with reduced, mid-range, or preserved ejection fraction. Between January 2014 and February 2017, 696 IS patients were enrolled. Of them, patients with sufficient echocardiographic data on SD were included in the analyses {n = 644 patients [median age 71 years (interquartile range 60-78), 61.5% male]}. In these patients, full assessment of DD was feasible in 549 patients without SD (94%). Prevalence of cardiac dysfunction and HF was as follows: SD 9.6% [95% confidence interval (CI) 7.6-12.2%]; DD in patients without SD 23.3% (95% CI 20.0-27.0%); and clinically overt HF 5.4% (95% CI 3.9-7.5%) with subcategories of HF with preserved ejection fraction 4.35%, HF with mid-range ejection fraction 0.31%, and HF with reduced ejection fraction 0.78%. In multivariable analysis, SD and fulfilment of HF criteria were associated with history of coronary heart disease [SD: odds ratio (OR) 3.87, 95% CI 1.93-7.75, P = 0.0001; HF: OR 2.29, 95% CI 1.04-5.05, P = 0.0406] and high-sensitive troponin T at baseline (SD: OR 1.78, 95% CI 1.31-2.42, P = 0.0003; HF: OR 1.66, 95% CI 1.17-2.33, P = 0.004); DD was associated with older age (OR 1.08, 95% CI 1.05-1.11, P < 0.0001) and treated hypertension vs. no hypertension (OR 2.84, 95% CI 1.23-6.54, P = 0.0405).

CONCLUSIONS

A substantial proportion of the study population exhibited subclinical and clinical cardiac dysfunction. SICFAIL provides reliable data on prevalence and determinants of SD, DD, and clinically overt HF in patients with acute IS according to current guidelines, enabling further clarification of its aetiological and prognostic role.

Prognostic utility of the assessment of diastolic function in patients undergoing cardiac resynchronization therapy

Conflicting data exist about the relationship between cardiac resynchronization therapy (CRT) and diastolic function. Aims of the study are to assess diastolic patterns in patients undergoing CRT according to the 2016 recommendations of the American Society of Echocardiography/European Association of Cardiovascular Imaging and to evaluate the prognostic value of diastolic dysfunction (DD) in CRT candidates. METHODS AND RESULTS: One-hundred ninety-three patients (age: 67 ± 11 years, QRS width: 167 ± 21 ms) were included in this multicentre prospective study. Mitral filling pattern, mitral tissue Doppler velocity, tricuspid regurgitation velocity, and indexed left atrial volume were used to classify DD from grade I to III. CRT-response, defined as a reduction of left ventricular (LV) end-systolic volume > 15% at 6-month follow-up (FU), occurred in 132 (68%) patients. The primary endpoint was a composite of heart transplantation, LV assisted device implantation, or all-cause death during FU and occurred in 29 (15%) patients. CRT was associated with a degradation of DD in non-responders. At multivariable analysis corrected for clinical variables, QRS duration, mitral regurgitation, CRT-response and LV dyssynchrony, grade I DD was associated with a better outcome (HR 0.37, 95% CI: 0.14-0.96). Non-responders with grade II-III DD had the worse prognosis (HR 4.36, 95%CI: 2.10-9.06). CONCLUSIONS: The evaluation of DD in CRT candidates allows the prognostic stratification of patients, independently from CRT-response.

Clinical and echocardiographic predictors of outcomes in patients with peripartum cardiomyopathy: A single centre, six month follow-up study

INTRODUCTION

Peripartum cardiomyopathy (PPCM) is an important cause of maternal mortality and morbidity. But, there is a paucity of prospective data on outcomes and prognostic markers in patients receiving contemporary evidence-based therapy, particularly in developing countries.

METHODS

This was a single centre, prospective, cohort study on 43 PPCM patients who were followed for 6 months. The primary endpoint was a composite incidence of decompensation related re-hospitalization, all-cause death, and poor recovery (defined as left ventricular ejection fraction, LVEF: <45% at 6 months). Multivariate logistic regression analysis was performed to identify the independent predictors and Kaplan-Meier plots for event (re-hospitalization or death) free survival were computed at their optimal cut-offs.

RESULTS

Mean LVEF at presentation was 34.7%. Two patients died during index hospitalization but there were no deaths during follow-up and 63.4% of patients had full LV recovery after discharge. 32.5% of the study population experienced the composite endpoint with high left atrial volume index (LAVi), and low right ventricular fractional area change (RVFAC) at presentation as independent predictors. Use of Inotropic therapy during index hospitalization (with dobutamine or levosimendan) and bromocriptine therapy were not associated with better outcome.

CONCLUSIONS

At the end of 6 months after PPCM diagnosis, about 61% of patients had full LV functional recovery with a mortality rate of 4.7%. RVFAC (<31.4% with 86% accuracy) and LAVi (>29.6 ml/m² with 72% accuracy) at presentation but not LVEF, predicts poor outcomes. Presence of both these risk factors at index hospitalization was associated with a significantly lower event free survival compared to patients without these predictors.

Characteristics and outcomes of transitions among heart failure categories: a prospective observational cohort study

Aims

Patients with heart failure (HF) are typically designated as having reduced, mid‐range, or preserved ejection fraction (EF) (HFrEF, HFmrEF, or HFpEF, respectively) because of the importance of left ventricular EF (LVEF) on therapeutic decisions and prognosis. However, such designations are not necessarily static, as there are many transitions among the three HF phenotypes during follow‐up. This prospective longitudinal cohort study sought to examine the HF transitions over time and their clinical characteristics, prognosis, and response to medical therapy.

Methods and results

We identified 1920 patients from a prospective cohort with a primary diagnosis of HF between 1 January 2007 and 31 December 2012. The enrolled HF patients were re‐classified into three groups on the basis of baseline and 1 year follow‐up echocardiography: HF with improved EF (HFiEF), HF with deteriorated EF (HFdEF), and HF with unchanged EF (HFuEF). The primary outcome was 5 year all‐cause mortality. According to 1 year follow‐up echocardiography, 490 (25.5%) were diagnosed as HFiEF, 179 (9.3%) as HFdEF, and 1251 (65.2%) as HFuEF. Ischaemic heart disease was an independent predictor of HFdEF, and beta‐blocker prescription was an independent predictor of HFiEF. During the 5 year follow‐up, patients with HFdEF had higher mortality, whereas patients with HFiEF had lower mortality. After adjustment, HFiEF, compared with HFuEF, was associated with a 62.1% decreased risk for mortality. Finally, the use of beta‐blockers was associated with improved prognosis of patients with HFiEF and HFuEF.

Conclusions

In this cohort of patients with HF, LVEF is a dynamic factor related to coexisting conditions and drug therapy. HFiEF and HFdEF are distinct HF phenotypes with different clinical outcomes than other phenotypes.

Prognostic utility of diastolic dysfunction and speckle tracking echocardiography in heart failure with reduced ejection fraction

Aims

We hypothesized that grading of diastolic dysfunction (DDF) according to two DDF grading algorithms and strain imaging yields prognostic information on all‐cause mortality in patients with heart failure with reduced ejection fraction (HFrEF).

Methods and results

We enrolled ambulatory HFrEF (left ventricular ejection fraction < 45%; N = 1 065) patients who underwent echocardiography and speckle tracking assessment of global longitudinal strain (GLS). Patients were stratified according to DDF grades (Grades I–III) according to two contemporary DDF grading algorithms. Prognostic performance was assessed by C‐statistics. Of the originally 1 065 enrolled patients, a total of 645 (61%) patients (age: 67 ± 11 years, male: 72%, ejection fraction: 27 ± 9%) were classified according to both DDF grading algorithms. Concordance between the algorithms was moderate (kappa = 0.48) and the reclassification rate was 33%. During a median follow‐up of 3.3 years (1.9, 4.7 years), 101 (16%) died from all causes. When comparing DDF Grade I vs. Grade III, both algorithms provided prognostic information [Nagueh: (hazard ratio) HR 2.09, 95% confidence interval (CI),1.32–3.31, P = 0.002; Johansen: HR 2.47, 95% CI, 1.57–3.87, P < 0.001]. However, when comparing DDF Grade II vs. Grade III, only the Johansen algorithm yielded prognostic information (Nagueh: HR 1.04, 95% CI, 0.60–1.77, P = 0.90; Johansen: HR 2.26, 95% CI, 1.35–3.77, P = 0.002). We found no difference in prognostic performance between the two algorithms (C‐statistics: 0.604 vs. 0.623, P = 0.24). Assessed by C‐statistics, the most powerful predictors of the endpoint from the two algorithms were E/e'‐ratio (C‐statistics: 0.644), tricuspid regurgitation velocity (C‐statistics: 0.625) and E/A‐ratio (C‐statistics: 0.602). When adding GLS to a combination of these predictors, the prognostic performance increased significantly (C‐statistics: 0.705 vs. C‐statistics: 0.634, P = 0.028).

Conclusions

Evaluation of DDF in patients with HFrEF yields prognostic information on all‐cause mortality. Furthermore, adding GLS to contemporary algorithms of DDF adds novel prognostic information.

Heart failure with mid-range ejection fraction and with preserved ejection fraction

The annual "heart report" published by the German Heart Foundation (Deutsche Herzstiftung) in December 2017 indicates that heart failure (ICD I50) remains the number one diagnosis of in-hospital-treated patients throughout Germany. For some time, the clinical diagnosis of heart failure has been verified by echocardiographic parameters as well as cardiac biomarkers that assist the clinician to rule in or rule out the presence of a failing heart, when used wisely. By introducing the term "heart failure with mid-range ejection fraction" (HFmrEF), the 2016 European Society of Cardiology (ESC) heart failure guidelines established a third heart failure entity, which was not necessarily seen as an improvement by the heart failure community. Nevertheless, half of all patients suffering from heart failure are now classified as having HFmrEF or heart failure with preserved ejection fraction (HFpEF), but the etiology and treatment options differ substantially. To elucidate this issue, the current review aims to highlight the key findings published to date. This should minimize the confusion that may have been generated by the new term "HFmrEF".

Concomitant diastolic dysfunction further interferes with cognitive performance in moderate to severe systolic heart failure

Background

Studies of the relevance of cardiac functional markers to cognitive performance in heart failure (HF) have primarily focused on systolic markers. In this study, we examine whether concomitant diastolic dysfunction further interferes with cognitive performance in memory, attention, and executive function in patients with HF.

Methods and results

In this cross-sectional correlational study, 82 patients completed face-to-face interviews for neuropsychological testing for cognitive evaluation. Echocardiographic data were obtained from a review of medical records. Mild to moderate (ejection fraction [EF] ≥ 30%) and severe (EF < 30%) systolic dysfunction were present in 55 (67.1%) and 27 (32.9%) patients, respectively, while 21 (26.3%) had diastolic dysfunction (E/e′ > 15). Those patients who had severe systolic dysfunction had significantly lower attention scores (Digit Span Test [DST] backward, t = 2.62, p = 0.011), while those with concomitant severe diastolic dysfunction had significantly lower verbal fluency (t = 2.84, p = 0.006) and executive function (Korean-Trail Making Test Part B) (t = -2.14, p = 0.036) scores than those without severe diastolic dysfunction. After controlling for age and education, systolic patients with HF with concomitant severe diastolic dysfunction had worse cognitive performance in verbal fluency than those without severe diastolic dysfunction (F = 4.33, p = 0.041, partial eta = 0.057). Concomitant moderate to severe systolic and severe diastolic dysfunction further reduced verbal fluency (F = 8.42, p = 0.005, partial eta = 0.106).

Conclusions

Cognitive performance, particularly executive function, was worse in patients with HF with systolic dysfunction when diastolic dysfunction was concomitantly present. Routine monitoring of and surveillance for diastolic dysfunction and cognitive screening are warranted in the management of patients with HF.

Diabetic retinopathy is associated with diastolic dysfunction in type 2 diabetic patients with non-ischemic dilated cardiomyopathy

BACKGROUND

To investigate the association between diabetic retinopathy (DR) and myocardial dysfunction in patients with type 2 diabetes and dilated cardiomyopathy (dCMP).

METHODS

Data were collected retrospectively from 89 patients with dCMP (46 with type 2 diabetes and 43 without diabetes) and no evidence of coronary artery disease. Echocardiographic parameters and laboratory data, including lipid profiles and fundus findings, were obtained from medical records. A left ventricular ejection fraction (LVEF) less than 40% was considered impaired systolic function, while an E/E' ratio greater than 15 was considered elevated left ventricular (LV) filling pressure.

RESULTS

Baseline characteristics show that LVEF was not significantly different between patients with and without diabetes or between diabetic patients with and without DR. Among the diastolic function parameters, patients with DR exhibited higher E/E' ratios (left ventricular filling pressures) than patients without DR (23.75 ± 13.37 vs 11.71 ± 3.50, P = 0.022). Logistic regression analysis revealed that statin use lowered the risk of impaired systolic dysfunction in all patients (odds ratio (OR) 0.33, 95% confidence interval (CI) 0.12-0.92, P = 0.034) and in patients with diabetes (OR 0.273, 95% CI 0.08-0.99, P = 0.049), while the presence of DR was associated with a higher risk of elevated LV filling filling pressure in patients with diabetes (OR 18.00, 95% CI 1.50-216.62, P = 0.023).

CONCLUSIONS

In conclusion, DR was associated with elevated LV filling pressure in patients with dCMP. DR may not only represent microvascular long-term complications in patients with diabetes but may also be associated with more advanced form of diastolic dysfunction among diabetic patients with cardiomyopathy.

Prognostic impact of diastolic dysfunction in systolic heart failure-A cross-project analysis from the German Competence Network Heart Failure

BACKGROUND

We investigated the modifying role and prognostic importance of diastolic dysfunction (DD) in patients with heart failure and systolic dysfunction (SD).

HYPOTHESIS

The echocardiographic evaluation of diastolic function in patients with SD provides further prognostic information.

METHODS

From the German Competence Network Heart Failure, 1046 heart failure patients with reduced left ventricular ejection fraction (LVEF; <50%) were echocardiographically studied and followed for a median of 5 years. SD was subdivided into nonsevere (LVEF 36%-49%) and severe (LVEF ≤35%); DD was subdivided into nonsevere (E/E' <15) and severe (E/E' ≥15).

RESULTS

In general, severe SD was associated with higher hazard ratios (HRs; 2-fold to 3.5-fold) for all endpoints (all-cause death, cardiac death, cardiovascular hospitalization, duration of hospitalization). Patients with severe SD had a 2.5-fold risk of death (95% confidence interval [CI]: 1.84-3.47, P < 0.001), and patients with severe DD showed a 1.8-fold risk (95% CI: 1.17-2.61, P = 0.004). Furthermore, we observed a strong interaction of SD and DD: concomitant severe DD in patients with moderate SD increased risk substantially (HR: 1.73, 95% CI: 1.16-2.6, P = 0.007); by contrast, in patients with severe SD, additional presence of severe DD added little or no risk (HR for interaction: 0.5-1.2).

CONCLUSIONS

In heart failure patients with reduced LVEF, the evaluation of diastolic function provides additional prognostic information. Although severe SD generally increased the risk for all endpoints, the degree of DD and its impact as a prognostic marker for overall and cardiovascular mortality appeared of particular relevance in subjects with nonsevere SD.