Abstract Background Respiratory sinus arrhythmia (RSA), a measure of cardiac vagal modulation, provides cardiac risk stratification information. RSA can be quantified from Holter recordings as the ...high-frequency component of heart rate variability or as the variability of RR intervals in individual respiratory cycles. However, as a risk predictor, RSA is neither exceptionally sensitive nor specific. Objectives This study aimed to improve RSA determination by quantifying the amount of sinus arrhythmia related to expiration (expiration-triggered sinus arrhythmia ETA) from short-term recordings of electrocardiogram and respiratory chest excursions, and investigated the predictive power of ETA in survivors of acute myocardial infarction. Methods Survivors of acute myocardial infarction (N = 941) underwent 30-min recordings of electrocardiogram and respiratory chest excursions. ETA was quantified as the RR interval change associated with expiration by phase-rectified signal averaging. Primary outcome was 5-year all-cause mortality. Univariable and multivariable Cox regression was used to investigate the association of ETA with mortality. Results ETA was a strong predictor of mortality, both in univariable and multivariable analysis. In a multivariable model including respiratory rate, left ventricular ejection fraction, diabetes mellitus, and GRACE score, ETA ≤0.19 ms was associated with a hazard ratio of 3.41 (95% confidence interval: 1.10 to 5.89, p < 0.0001). In patient subgroups defined by abnormal left ventricular ejection fraction, increased respiratory rate, high GRACE score, or presence of diabetes mellitus, patients were classified as high or low risk on the basis of ETA. Conclusions Expiration-triggered sinus arrhythmia (ETA) is a potent and independent post-infarction risk marker.
Numerous patients are treated with the MitraClip, although they do not fulfill the stringent inclusion criteria of the Endovascular Valve Edge-to-Edge Repair Study (EVEREST) trials. The outcome of ...those patients is not well known. Therefore, we compared the long-term outcome after MitraClip treatment between patients who matched (group 1) and did not match (group 2) the EVEREST criteria. One hundred thirty-four consecutive patients were treated from September 2009 to July 2012: 59 patients (44%) in group 1 versus 75 patients (56%) in group 2. Investigated end points were acute procedural success (for group 1 vs 2: 97% vs 95%; p = 0.694), all-cause mortality (28% vs 27%; p = 0.656), reintervention (RI) rate (11% vs 37%; p = 0.010), and improvement in mitral regurgitation (MR) (−1.3 ± 1 vs −1.5 ± 1, p = 0.221) and in New York Heart Association functional class (−0.7 ± 1 vs −0.9 ± 0.8, p = 0.253) during the follow-up of 33 months (27.9 to 38.3). The morphologic extent of a flail leaflet was an independent predictor for RI. In conclusion, although the overall outcome was comparable between both groups, recurrent symptomatic MR with need for RI was higher in group 2, mainly because of complex valve pathologies: especially flail width >15 mm and gap ≥10 mm. Improvements in the interventional strategy are warranted for reducing the need for RI in patients with primary MR.
The clinical outcome of patients with severe primary and secondary mitral regurgitation (MR) and heart failure or significantly reduced left ventricular ejection fraction (LVEF) who underwent ...percutaneous mitral valve repair (pMVR) is yet not well known. This study compares midterm outcome of patients with severe left ventricular dysfunction (EF ≤30%) versus patients with slightly or moderately reduced or normal LVEF (EF >30%) after pMVR. One hundred thirty-six consecutive patients were enrolled: 42 patients displayed severe left ventricular dysfunction, group 1 (logistic EuroSCORE I 27.7 ± 21.8%; secondary MR in 37 patients), and 94 patients displayed slightly or moderately reduced or normal LVEF, group 2 (logistic EuroSCORE I 17 ± 18.2%; secondary MR in 21 patients). The primary efficacy endpoint was death of any cause, repeat mitral valve intervention, and/or New York Heart Association class ≥III, which was reached in 31% of patients in group 1 versus 40% in group 2 (p = 0.719) at a median follow-up of 371 days. MR, graded by transthoracic echocardiography, was reduced in both groups (p <0.001) and New York Heart Association class improved in each group (p <0.001), with no differences between groups (p >0.05). In conclusion, at midterm follow-up, the pMVR provided significant clinical benefits with comparable results achieved both in patients with significantly reduced and in patients with moderately reduced to normal LVEF. Thus, pMVR represents a feasible and effective treatment in high-risk patients who otherwise have limited therapeutic options and no safe option to reduce MR.
Low baroreflex sensitivity (BRS) indicates poor prognosis after acute myocardial infarction. Noninvasive BRS assessment is complicated by nonstationarities and noise in electrocardiogram and pressure ...signals. Phase-rectified signal averaging is a novel signal processing technology overcoming these problems.
To prospectively validate a BRS measure (baroreflex sensitivity assessed by means of phase-rectified signal averaging BRS(PRSA)) based on this technology.
Nine hundred forty-one consecutive acute myocardial infarction survivors aged 80 years or younger in sinus rhythm were prospectively enrolled at 2 German university hospitals. All patients underwent 30-minute recordings of electrocardiogram and arterial blood pressures (Portapres; TNO-TPD Biomedical Instrumentation, Amsterdam, Netherlands) within the first 2 weeks after myocardial infarction. BRS(PRSA) was prospectively dichotomized at 1.58 ms/mm Hg. Primary end point was all-cause mortality at 5 years. Multivariable analyses included Global Registry of Acute Coronary Events score (dichotomized at ≥120), sex, BRS(PRSA), left ventricular ejection fraction (dichotomized at ≤35%), and diabetes mellitus. BRS(PRSA) was compared with 3 standard noninvasive BRS measures, that is, the sequence method, the transfer function method, and the correlation method.
During follow-up, 72 patients (7.7%) died. BRS(PRSA) stratified the study population into a high-risk group of 405 patients (≤1.58 ms/mm Hg) with an estimated 5-year mortality of 14.2% and a low-risk group of 536 patients (>1.58 ms/mm Hg) with a 5-year mortality of 2.8% (P <.0001). On multivariable analysis, BRS(PRSA) ≤ 1.58 ms/mm Hg was associated with a hazard ratio of 3.1 (confidence interval 1.7-5.6; P = .001). Predictive power of BRS(PRSA) ≤ 1.58 ms/mm Hg was particularly strong in patients with a Global Registry of Acute Coronary Events score of ≥120 or with a left ventricular ejection fraction of ≤35%.
BRS(PRSA) is a powerful and independent predictor of mortality in postinfarction patients especially when assessed in patients with a Global Registry of Acute Coronary Events score of ≥120 or a left ventricular ejection fraction of ≤35%.
Type 2 diabetes mellitus is a well-established risk factor for atherosclerosis, but its contribution to sudden cardiac death (SCD) risk after myocardial infarction (MI) is not well defined.
The ...purpose of this study was to compare the incidence and time-dependent risk of SCD in diabetic patients versus nondiabetic patients during 5-year follow-up after acute MI.
A total of 3,276 patients were enrolled at the time of acute MI between 1996 and 2005. Mean age at entry was 60 ± 11 years, and the cohort was followed until 2009. At entry into the study, diabetes was present in 629 (19.2%) patients. The primary endpoint was SCD, and the secondary endpoints were non-SCD and all-cause mortality.
Among diabetic patients, the incidence of SCD was higher (5.9%) than in nondiabetic patients (1.7%), with a hazard ratio (HR) of 3.8 (95% confidence interval CI 2.4-5.8; P <.001) and adjusted HR of 2.3 (95% CI 1.4-3.8; P <.01). In diabetic patients with left ventricular ejection fraction >35%, the incidence of SCD was nearly identical to that of nondiabetic patients with ventricular ejection fraction ≤35% (4.1% vs 4.9%; P = .48). An excess in the incidence of non-SCD began to appear among diabetic patients within the first 6 months of follow-up (P <.001) but not in the incidence of SCD (P = .09). The excess in SCD among diabetic patients began to appear more than 6 months after the index event.
Patients with type 2 diabetes are at higher risk for SCD after MI than are nondiabetic patients. The incidence of SCD in post-MI type 2 diabetic patients with left ventricular ejection fraction >35% is equal to that of nondiabetic patients with left ventricular ejection fraction <35%.
To the Editor: Survivors of acute myocardial infarction (MI) are at substantial risk of subsequent death due to progressive heart failure, arrhythmic events, and/or reinfarction. Among patients with ...LVEF <=35% (i.e., ICD candidates), increased NRR identifies a group of patients with frequent N-SCD (i.e., a mode of death likely not implantable cardioverter-defibrillator ICD preventable). ...it cannot be excluded that ICD implantation might be harmful in some of these patients.
Abstract A method for counting episodes of uninterrupted beat-to-beat heart rate decelerations was developed. Methods The method was set up and evaluated using 24-hour electrocardiogram Holter ...recordings of 1455 (training sample) and 946 (validation sample) postinfarction patients. During a median follow-up of 24 months, 70, 46, and 19 patients of the training sample suffered from total, cardiac, and sudden cardiac mortality, respectively. In the validation sample, these numbers were 39, 25, and 15. Episodes of consecutive beat-to-beat heart rate decelerations (deceleration runs DRs) were characterized by their length. Results Deceleration runs of 2 to 10 cycles were significantly less frequent in nonsurvivors. Multivariate model of DRs of 2, 4, and 8 cycles identified low-, intermediate-, and high-risk groups. In these groups of the training sample, the total mortalities were 1.8%, 6.1%, and 24%, respectively. In the validation sample, these numbers were 1.8%, 4.1%, and 21.9%. Conclusion Infrequent DRs during 24-hour Holter indicate high risk of postinfarction mortality.
Abstract Background We recently reported that nocturnal respiratory rate (NRR) predicts non-sudden cardiac death in survivors of myocardial infarction (MI). Here, we present the details of the ...technique deriving NRR from ECG recordings. Methods Continuous ECG and respiratory chest excursions were simultaneously recorded in 941 MI survivors who were followed-up for 5-years. Mean respiratory rate was derived from the ECG based on RR intervals, QRS amplitudes, and QRS vectors and compared to chest belt measurements. NRR was calculated from Holter-ECGs accordingly using the same ECG processing. Results Directly-measured and ECG-derived respiratory rates were in good agreement. Areas under the ROC curve for 10-min-ECG- and Holter-derived respiratory rate were well in the confidence intervals of that of the chest belt measurement. The optimum dichotomy of NRR for the prediction of mortality was ≥ 18.6 breaths per minute. Conclusions The mean respiratory rate can be precisely derived from continuous ECGs.
Abstract Background Women have unfavorable prognosis after myocardial infarction (MI). This text describes sex differences in mortality and in the power of risk predictors in contemporarily-treated ...MI patients. Methods A population of 4141 MI patients (26.5% females) was followed up for 5 years. Effects of sex and age on total mortality were investigated by multivariable Cox analysis. Mortality predictors were investigated by receiver-operator characteristics analysis. Stepwise multivariable Cox regression was used to create sex-specific predictive models. Results Thirty-day mortality was 1.5-fold higher in women. However, sex was not a significant mortality predictor in a model adjusted for age. Predictors for 5-year mortality performed differently in male and female patients. In women, a sex-specific model provided better risk stratification than a sex-neutral model. Conclusion The unfavorable prognosis of female MI patients can be explained by advanced age. Sex-specific predictive models might improve risk stratification in female survivors of acute MI.
Abstract Background Assessment of spontaneous baroreflex sensitivity (BRS), an index of autonomic function, poses practical challenges. In this pilot study, we propose a novel technique for ...assessment of spontaneous BRS based on bivariate phase-rectified signal averaging (PRSA). This is an extension of the monovariate PRSA technology used for calculation of deceleration capacity. Methods A prospective, observational study was conducted in a training cohort of 146 patients with heart failure (New York Heart Association class 2.7 ± 0.8, left ventricular ejection fraction 23.6% ± 9.0%) presenting with sinus rhythm. In all patients, 10-minute recordings of ECG and arterial and blood pressure were obtained in the supine resting position. The algorithm for BRS assessment based on bivariate PRSA (BRSPRSA ) included (1) identification of heartbeat intervals occurring at the time of systolic pressure increases, (2) selection of heartbeat adjacent interval sections, (3) alignment and (4) averaging of these segments, and (5) quantification of the average heart beat interval change by Haar wavelet analysis. Primary end point was death of any cause. During mean follow-up of 2.7 ± 1.1 years, 42 patients (28.8%) died. Results BRSPRSA was significantly associated with the primary end point (3.7 ± 5.3 ms vs −0.33 ± 6.6 ms in survivors and nonsurvivors, respectively). BRSPRSA yielded an area under the receiver operating characteristics curve of 69.8% (95% confidence interval, 59.9-79.7), which was comparable to the area under the curve of left ventricular ejection fraction (70.4%; 95% confidence interval, 61.3-79.5). Using the optimum dichotomy for BRSPRSA of 1.14 milliseconds, 52 (36%) patients had an abnormal BRSPRSA . The 3-year mortality risk of these patients was 45.3% compared to 19.0% in patients with normal BRSPRSA . On multivariate analysis, abnormal BRSPRSA was an independent risk factor from left ventricular ejection fraction ≤ 30% and New York Heart Association class > II. Conclusion BRSPRSA is an independent and strong predictor of mortality in patients with heart failure. Prospective validation and comparisons with standard measures of BRS are needed.
PDF
