Gregg S. Pressman

Association of Atrial Fibrillation and Obstructive Sleep Apnea

Background—Obstructive sleep apnea (OSA) is associated with recurrent atrial fibrillation (AF) after electrocardioversion. OSA is highly prevalent in patients who are male, obese, and/or hypertensive, but its prevalence in patients with AF is unknown. Methods and Results—We prospectively studied consecutive patients undergoing electrocardioversion for AF (n=151) and consecutive patients without past or current AF referred to a general cardiology practice (n=312). OSA was diagnosed with the Berlin questionnaire, which is validated to identify patients with OSA. We also assessed its accuracy compared with polysomnography in a sample of the study population. Groups were compared with the 2-tailed t, Wilcoxon, and &khgr;2 tests. Logistic regression modeled the association of AF and OSA after adjustment for relevant covariates. Patients in each group had similar age, gender, body mass index, and rates of diabetes, hypertension, and congestive heart failure. The questionnaire performed with 0.86 sensitivity, 0.89 specificity, and 0.97 positive predictive value in our sample. The proportion of patients with OSA was significantly higher in the AF group than in the general cardiology group (49% versus 32%, P=0.0004). The adjusted odds ratio for the association between AF and OSA was 2.19 (95% CI 1.40 to 3.42, P=0.0006). Conclusions—The novel finding of this study is that a strong association exists between OSA and AF, such that OSA is strikingly more prevalent in patients with AF than in high-risk patients with multiple other cardiovascular diseases. The coinciding epidemics of obesity and AF underscore the clinical importance of these results.

Day-Night Variation of Acute Myocardial Infarction in Obstructive Sleep Apnea

OBJECTIVES This study sought to evaluate the day-night variation of acute myocardial infarction (MI) in patients with obstructive sleep apnea (OSA). BACKGROUND Obstructive sleep apnea has a high prevalence and is characterized by acute nocturnal hemodynamic and neurohormonal abnormalities that may increase the risk of MI during the night. METHODS We prospectively studied 92 patients with MI for which the time of onset of chest pain was clearly identified. The presence of OSA was determined by overnight polysomnography. RESULTS For patients with and without OSA, we compared the frequency of MI during different intervals of the day based on the onset time of chest pain. The groups had similar prevalence of comorbidities. Myocardial infarction occurred between 12 am and 6 am in 32% of OSA patients and 7% of non-OSA patients (p = 0.01). The odds of having OSA in those patients whose MI occurred between 12 am and 6 am was 6-fold higher than in the remaining 18 h of the day (95% confidence interval: 1.3 to 27.3, p = 0.01). Of all patients having an MI between 12 am and 6 am, 91% had OSA. CONCLUSIONS The diurnal variation in the onset of MI in OSA patients is strikingly different from the diurnal variation in non-OSA patients. Patients with nocturnal onset of MI have a high likelihood of having OSA. These findings suggest that OSA may be a trigger for MI. Patients having nocturnal onset of MI should be evaluated for OSA, and future research should address the effects of OSA therapy for prevention of nocturnal cardiac events.

Infective endocarditis epidemiology over five decades: a systematic review.

Aims To Assess changes in infective endocarditis (IE) epidemiology over the last 5 decades. Methods and Results We searched the published literature using PubMed, MEDLINE, and EMBASE from inception until December 2011. Data From Einstein Medical Center, Philadelphia, PA were also included. Criteria for inclusion in this systematic review included studies with reported IE microbiology, IE definition, description of population studied, and time frame. Two authors independently extracted data and assessed manuscript quality. One hundred sixty studies (27,083 patients) met inclusion criteria. Among hospital-based studies (n=142; 23,606 patients) staphylococcal IE percentage increased over time, with coagulase-negative staphylococcus (CNS) increasing over each of the last 5 decades (p<0.001) and Staphylococcus aureus (SA) in the last decade (21% to 30%; p<0.05). Streptococcus viridans (SV) and culture negative (CN) IE frequency decreased over time (p<0.001), while enterococcal IE increased in the last decade (p<0.01). Patient age and male predominance increased over time as well. In subgroup analysis, SA frequency increased in North America, but not the rest of the world. This was due, in part, to an increase in intravenous drug abuse IE in North America (p<0.001). Among population-based studies (n=18; 3,477 patients) no significant changes were found. Conclusion Important changes occurred in IE epidemiology over the last half-century, especially in the last decade. Staphylococcal and enterococcal IE percentage increased while SV and CN IE decreased. Moreover, mean age at diagnosis increased together with male:female ratio. These changes should be considered at the time of decision-making in treatment of and prophylaxis for IE.

Dynamic Changes of Left Ventricular Performance and Left Atrial Volume Induced by the Mueller Maneuver in Healthy Young Adults and Implications for Obstructive Sleep Apnea, Atrial Fibrillation, and Heart Failure

Using the Mueller maneuver (MM) to simulate obstructive sleep apnea (OSA), our aim was to investigate acute changes in left-sided cardiac morphologic characteristics and function which might develop with apneas occurring during sleep. Strong evidence supports a relation between OSA and both atrial fibrillation and heart failure. However, acute effects of airway obstruction on cardiac structure and function have not been well defined. In addition, it is unclear how OSA might contribute to the development of atrial fibrillation and heart failure. Echocardiography was used in healthy young adults to measure various parameters of cardiac structure and function. Subjects were studied at baseline, during, and immediately after performance of the MM and after a 10-minute recovery. Continuous heart rate, blood pressure, and pulse oximetry measurements were made. During the MM, left atrial (LA) volume index markedly decreased. Left ventricular (LV) end-systolic dimension increased in association with a decrease in LV ejection fraction. On release of the maneuver, there was a compensatory increase in blood flow to the left side of the heart, with stroke volume, ejection fraction, and cardiac output exceeding baseline. After 10 minutes of recovery, all parameters returned to baseline. In conclusion, sudden imposition of severe negative intrathoracic pressure led to an abrupt decrease in LA volume and a decrease in LV systolic performance. These changes reflected an increase in LV afterload. Repeated swings in afterload burden and chamber volumes may have implications for the future development of atrial fibrillation and heart failure.

Under-diagnosis of Sleep Apnea in Patients after Acute Myocardial Infarction

TO THE EDITOR: Obstructive sleep apnea (OSA) is highly prevalent in the general population and has been associated with arrhythmias, hypertension, stroke, and heart failure (1). Identification of OSA in cardiovascular patients is especially important as untreated OSA may be accompanied by increased cardiovascular events, and this risk may be attenuated by treatment with continuous positive airway pressure (CPAP)(2). We sought to investigate how the rates of recognition and diagnosis of obstructive sleep apnea compare to the actual prevalence of OSA in patients after myocardial infarction (MI). This study comprised two parts: a chart review of consecutive patients presenting with acute MI, and a prospective evaluation of MI patients who were recruited to undergo polysomnography. These studies were approved by the Institutional Review Board. First, we reviewed the medical records of 798 consecutive patients who were hospitalized with a diagnosis of acute MI between January and September 2007. Electronic records, including admission and dismissal notes were searched for diagnosed or suspected sleep disordered breathing, and especially for mention of OSA during the MI hospitalization. In the event of several hospital admissions for the same patient, only the first admission was used in our analysis. We further prospectively studied 74 patients who were hospitalized with acute myocardial infarction between 2004 and 2008, and were recruited to undergo attended overnight polysomnography, which is the gold standard in the diagnosis of OSA (Compumedics Siesta Wireless Sleep Recorder, Oxford Instruments, UK). All polysomnographies were performed within 6 weeks of the MI hospitalization, and scored by standard criteria (1). OSA was defined as present when the apnea hypopnea index (AHI) was >5. The diagnosis of MI was based on standard guidelines, and was made by the attending physicians who were blinded to this study. Patients were approached during their MI hospitalization, and their participation was based on their consent and availability of the study personnel and equipment. There was no systematic selection for specific demographic or patient characteristics. A review of electronic and paper records of these patients was also performed in similar fashion to that of the first part of our study. Between January and September 2007 there were 798 patients admitted to our institution with the diagnosis of acute MI. The mean age of this cohort was 69±14 years, and 512 (64%) were male. Diagnosed and suspected OSA was recorded in 97 (12%) patient records. The prospective cohort of 74 patients had a mean age of 62±13 years, and 46 (78%) were male. On review of their hospital records, 10 (14%) had documentation of diagnosed or suspected OSA. All of these patients underwent overnight polysomnography (PSG). For this group the mean AHI was 17±18 events/hour. OSA was present in 51 (69%), and severe OSA (AHI >15) in 30 (41%) patients. The main finding of this study was the low rate of documented or suspected OSA in patients hospitalized for acute MI, contrasting with the high prevalence of OSA in those in whom we conducted prospective PSG studies. This suggests a lack of awareness and recognition of OSA during treatment of acute MI. A high prevalence of OSA in the unselected general population has been well documented (1). Our results suggest that only 12 percent of patients hospitalized with acute MI had documentation of diagnosed or suspected OSA. When prospectively evaluated by overnight PSG a subgroup of patients had a much higher actual prevalence of OSA (over two thirds had at least mild OSA) but even in these patients with proven sleep apnea the possibility of OSA was documented in only 14 percent of patients. There are several limitations to our study. First, documentation in the medical record does not necessarily reflect the entire scope of medical evaluation; it is possible that in some patients OSA was suspected and they were verbally recommended to have an OSA evaluation which was not documented in the records, or this was left for a follow-up visit. Even so, it would be advantageous to arrange for screening for OSA during the hospitalization, just as we routinely initiate aspirin, beta-blocker, statin, and ACE inhibitor therapy before patient discharge. Cardiovascular disease patients with untreated severe OSA are thought to have worse cardiovascular outcomes (2,3), which may be improved with CPAP. Randomized controlled trials testing this assumption are lacking. Demonstrated beneficial effects of CPAP could lead to significant practice and guidelines changes. An absence of such clinical trials may help explain the relatively low awareness of OSA as an important consideration in the patient with MI.

Primary cardiac tumors.

Primary cardiac tumors are a rare entity compared to tumors that metastasize to the heart. Patients with such tumors may be asymptomatic. Many cases are found incidentally during evaluation of an unrelated medical condition. It is important for the clinician to have a high index of suspicion when evaluating a patient presenting with signs and systemic symptoms concerning possible malignancy, plus cardiac specific symptoms or complications. These can include new onset dyspnea, congestive heart failure, arrhythmias or murmurs varying with body positions. Imaging, particularly the use of echocardiography, remains the cornerstone of diagnosis, and may be combined with new imaging modalities of cardiac CT and MRI. The aim of this paper is to describe the epidemiology and pathophysiology of the various benign and malignant primary cardiac tumors.

Changes in Left and Right Ventricular Mechanics During the Mueller Maneuver in Healthy Adults A Possible Mechanism for Abnormal Cardiac Function in Patients With Obstructive Sleep Apnea

Background—Obstructive sleep apnea is highly prevalent in patients with cardiovascular disease and has detrimental effects on systolic and diastolic function of the ventricles. In this research, the changes in strain (S) and strain rate (SR) during the performance of the Mueller maneuver (MM) in an effort to better understand how negative intrathoracic pressures affect ventricular mechanics. Methods and Results—The MM was performed to maintain a target intrathoracic pressure of −40 mm Hg. Echocardiography was used to measure various parameters of cardiac structure and function. Myocardial deformation measurements were performed using tissue speckle tracking. Twenty-four healthy subjects (9 women; mean age, 30±6 years) were studied. Global left ventricular longitudinal S in systole and SR in early filling were significantly decreased during the MM (S: baseline, −17.0±1.6%; MM, −14.5±2.2%; P<0.0001, SR: baseline, 1.09±0.20 s−1; MM, 0.92±0.21 s−1; P=0.01). Global right ventricular longitudinal S was also significantly decreased during the MM (baseline, −22.0±3.1%; MM, −17.2±2.5%; P<0.0001), as was global right ventricular longitudinal systolic SR (baseline, −1.34±0.35 s−1; MM, −1.02±0.21 s−1; P=0.0006). Conclusions—Left ventricular and right ventricular longitudinal deformation are significantly reduced during the MM. These results suggest that negative intrathoracic pressure during apnea may contribute to changes in myocardial mechanics. These results could help explain the observed changes in left ventricular and right ventricular mechanics in patients with obstructive sleep apnea.

Sleep-Disordered Breathing and Excessive Daytime Sleepiness in Patients With Atrial Fibrillation

BACKGROUND An important consequence of sleep-disordered breathing (SDB) is excessive daytime sleepiness (EDS). EDS often predicts a favorable response to treatment of SDB, although in the setting of cardiovascular disease, particularly heart failure, SDB and EDS do not reliably correlate. Atrial fibrillation (AF) is another highly prevalent condition strongly associated with SDB. We sought to assess the relationship between EDS and SDB in patients with AF. METHODS We conducted a prospective study of 151 patients referred for direct current cardioversion for AF who also underwent sleep evaluation and nocturnal polysomnography. The Epworth Sleepiness Scale (ESS) was administered prior to polysomnography and considered positive if the score was ≥ 11. The apnea-hypopnea index (AHI) was tested for correlation with the ESS, with a cutoff of ≥ 5 events/h for the diagnosis of SDB. RESULTS Among the study participants, mean age was 69.1 ± 11.7 years, mean BMI was 34.1 ± 8.4 kg/m(2), and 76% were men. The prevalence of SDB in this population was 81.4%, and 35% had EDS. The association between ESS score and AHI was low (R(2) = 0.014, P = .64). The sensitivity and specificity of the ESS for the detection of SDB in patients with AF were 32.2% and 54.5%, respectively. CONCLUSIONS Despite a high prevalence of SDB in this population with AF, most patients do not report EDS. Furthermore, EDS does not appear to correlate with severity of SDB or to accurately predict the presence of SDB. Further research is needed to determine whether EDS affects the natural history of AF or modifies the response to SDB treatment.

Improvement in Left Ventricular Systolic and Diastolic Performance During Ranolazine Treatment in Patients With Stable Angina

Purpose: Ranolazine is a novel antianginal medication that acts by ameliorating disturbed sodium and calcium homeostasis. By preventing myocyte sodium and calcium overload, ranolazine also have potential beneficial effects on myocardial function. Experimental models support this concept, as do 2 small studies in human participants receiving ranolazine intravenously. We evaluated changes in parameters of left ventricular function in stable angina patients treated with oral ranolazine. Methods: Twenty-two participants were enrolled with Doppler echocardiography performed at baseline and a mean of 2 months after initiation of treatment. Results: Global left ventricular function, as assessed by the myocardial performance index, was significantly improved on drug therapy (P < .0001). This was due to improvement in both diastolic and systolic parameters. Of 21 patients, 17 reported less angina and 8 patients reported an increase in activity level. Conclusions: We report improved parameters of left ventricular function in response to ranolazine as used in the clinical setting.

Can total cardiac calcium predict the coronary calcium score

BACKGROUND Mitral annular calcification (MAC) shares the same risk factors as atherosclerosis and is associated with coronary artery disease as well as cardiovascular events. However, sensitivity and positive predictive value are low. We hypothesized that a global echocardiographic calcium score would better predict coronary atherosclerotic burden, as assessed by coronary artery calcium score (CAC), than MAC alone. METHODS An echocardiographic score was devised to measure global cardiac calcification in a semi-quantitative manner; this included calcification in the aortic valve and root, the mitral valve and annulus, and the sub-mitral apparatus. This score, and a simplified version, were compared with a similar calcification score by CT scan, as well as the CAC. RESULTS There was a good correlation between the two global calcification scores; the echocardiographic score also correlated with CAC. Using CAC >400 as a measure of severe coronary atherosclerosis, an echocardiographic score ≥5 had a positive predictive value of 60%. Importantly, the simplified score performed equally well (≥3 had a positive predictive value of 62%). CONCLUSIONS Global cardiac calcification, assessed by CT scan or echocardiography, correlates with the extent of coronary calcium. A semi-quantitative calcium score can be easily applied during routine echocardiographic interpretation and can alert the reader to the possibility of severe coronary atherosclerosis.