Missed diagnosis of severe symptomatic aortic stenosis

A review of the pathophysiology, diagnosis, and treatment of aortic valve stenosis in elderly patients

Elderly patients experiencing valvular aortic stenosis (AS) show an increased prevalence of coronary risk factors, coronary artery disease, and other atherosclerotic vascular diseases. Angina pectoris, syncope or near syncope, and congestive heart failure are the 3 classic manifestations of severe AS in patients. Prolonged duration and late peaking of an aortic systolic ejection murmur best differentiate severe AS from mild AS upon physical examination of the patient. Doppler echocardiography is used to diagnose the severity of patient AS. In the article, indications for aortic valve replacement (AVR) in patients, the use of warfarin after AVR in patients with mechanical prostheses, and the use of aspirin or warfarin after AVR in patients with bioprosthesis are discussed. Transcatheter aortic valvular replacement should be performed in non-operable patients with symptomatic severe AS to improve their survival and quality of life rather than using regular medical management of the condition.

Atrial fibrillation in aortic stenosis--echocardiographic assessment and prognostic importance

Background

Atrial fibrillation (AFib) exists more frequently in patients with aortic stenosis (AS) than in patients without, and AFib may be a sign of progressive deterioration of AS. Echocardiographic assessment of AS in sinus rhythm is well documented, however, little is known about AFib in AS since such patients often are excluded from clinical echocardiographic trials.

Aim

The purpose of this study was to assess the prognostic importance of AFib in AS.

Methods

The study was designed as a single-center case-control study. Patients with AS and AFib were enrolled as cases (n = 103) and subsequently matched to controls (103 patients with AS but sinus rhythm). Cases and controls were matched according to age, gender and severity of AS. Primary outcome was all cause mortality and follow-up was 100% complete.

Results

Compared to controls the group with AFib had lower mean ejection fraction (42% vs. 49%; p < 0.001) and stroke volume (47 mL vs. 55 mL; p = 0.004), but higher heart rate (81 bpm vs. 68 bpm; p < 0.001) and no significant difference with regard to cardiac output (3.8 L vs. 4.0 L; p = 0.29). Accordingly, aortic jet velocity and gradients were significantly lower in AFib compared to controls but there were no differences (p = 0.38) in aortic valve area calculated by the continuity equation. During a median follow-up of 2.3 years (IQR: 1.2-3.6), 70 (34%) patients with AS died: 42 patients with AFib and 28 patients with sinus rhythm (p < 0.02). After adjusting for echocardiographic significant differences, AFib remained an independent predictor of mortality (HR 2.72 (95% CI: 1.12–6.61), p < 0.03). There was no significant interaction (p = 0.62) between AFib and AS on the risk of mortality, indicating that AFib predicted bad outcome regardless of the severity of AS.

Conclusions

AFib is an independent risk factor in patients with AS and the prognostic impact of AFib seems to be the same despite the severity of AS.

Aortic stenosis

Patients with aortic stenosis (AS) have an increased prevalence of coronary risk factors, coronary artery disease, and other atherosclerotic vascular disease and an increased incidence of coronary events and death. Statins may reduce the progression of AS. Angina pectoris, syncope or near syncope, and heart failure are the three classic manifestations of severe AS. Prolonged duration and late peaking of an aortic systolic ejection murmur best differentiate severe AS from mild AS on physical examination. Doppler echocardiography is used to diagnose the presence and severity of AS. Once symptoms develop, aortic valve replacement (AVR) should be performed in patients with severe or moderate AS. Warfarin should be administered indefinitely after AVR in patients with a mechanical aortic valve and in patients with a bioprosthetic aortic valve who have either atrial fibrillation, prior thromboembolism, left ventricular systolic dysfunction, or a hypercoagulable condition. Patients with a bioprosthetic aortic valve without any of these four risk factors should be treated with aspirin 75-100 mg daily.

Valvular Aortic Stenosis in the Elderly

Elderly patients with valvular aortic stenosis have an increased prevalence of coronary risk factors, of coronary artery disease, and evidence of other atherosclerotic vascular diseases. Statins may reduce the progression of aortic stenosis (AS). Angina pectoris, syncope or near syncope, and congestive heart failure are the 3 classic manifestations of severe AS. Prolonged duration and late peaking of an aortic systolic ejection murmur best differentiate severe AS from mild AS on physical examination. Doppler echocardiography is used to diagnose the prevalence and severity of AS. The indications for cardiac catheterization and the medical management of AS are discussed. Once symptoms develop, aortic valve replacement (AVR) should be performed in patients with severe or moderate AS. Other indications for AVR are discussed. Warfarin should be administered indefinitely after AVR in patients with a mechanical aortic valve and in patients with a bioprosthetic aortic valve who have either atrial fibrillation, prior thromboembolism, left ventricular systolic dysfunction, or a hypercoagulable condition. Patients with a bioprosthetic aortic valve without any of these 4 risk factors should be treated with aspirin 75-100 mg daily.

Aortic stenosis and the failing heart

The combination of aortic stenosis and left-ventricular dysfunction is a challenging situation for the physician. Diagnosis of this condition requires a detailed evaluation to understand the etiology and reversibility of the ventricular dysfunction and to accurately determine the real severity of the stenosis. Whether the aortic stenosis the cause of the left ventricular failure or is an independent disease has significant diagnostic, prognostic and therapeutic implications. Dobutamine echocardiography provides critical information to determine the real severity and the left ventricle's potential to recover (contractile reserve). Attempts to delay the progression of the aortic stenosis with medical treatment have been limited, and valve replacement remains the hallmark of ultimate treatment. If surgery is inadvertently delayed, left ventricular systolic dysfunction will result in clinically evident congestive heart failure and this situation carries a very high short-term mortality. Aortic valve replacement in this setting improves the outcome, but perioperative mortality is high, and particularly when coronary revascularization is also needed, there is no ventricular contractile reserve and transvalvular gradients are low. Adequate timing of surgery is extremely important and increasingly more difficult. Management decisions should be tailored by the results of dobutamine echocardiography and made on a case-by-case basis.

Evaluation of a hand carried cardiac ultrasound device in an outpatient cardiology clinic

OBJECTIVE

To determine the diagnostic potential of a hand carried cardiac ultrasound (HCU) device (OptiGo, Philips Medical Systems) in a cardiology outpatient clinic and to compare the HCU diagnosis with the clinical diagnosis and diagnosis with a full featured standard echocardiography (SE) system.

METHODS

300 consecutive patients took part in the study. The HCU examination was performed by an experienced echocardiographer before patients visited the cardiologist. The echocardiographer noted whether the HCU device was able to confirm or reject the referral diagnosis, which abnormality was detected, and whether SE investigation was necessary. Physical examination by a cardiologist followed and thereafter, whenever required, a complete study with an SE was carried out. The HCU data were compared with the clinical diagnosis of the cardiologist and the SE diagnosis in a blinded manner.

RESULTS

The cardiologist referred 203 of 300 patients for an SE study and 13 patients for transoesophageal echocardiography. In 84 patients no further examination was considered necessary. HCU echocardiography was able to confirm or reject the suspected clinical diagnosis in 159 of 203 (78%) patients. In 44 of 203 (22%) patients SE Doppler was needed. Agreement between the HCU device and the SE system for the detection of major abnormalities was excellent (98%). The HCU device missed 4% of the major findings. Among the 84 patients not referred for an SE, the HCU device detected unsuspected major abnormalities missed with the physical examination in 14 (17%).

CONCLUSION

Integration of an HCU device with the physical examination augments the yield of information.

Unsuspected clinically important findings detected with a small portable ultrasound device in patients admitted to a general medicine service

OBJECTIVE

We sought to determine whether physicians with training in echocardiography could successfully use a small echocardiographic device to detect occult cardiovascular disease in patients admitted to a general medical service.

METHODS

In all, 103 consecutive patients had a physician-performed bedside echocardiographic examination with a small portable ultrasound device.

RESULTS

Of patients, 70% did not have a clinical indication for echocardiography and of these patients, 39% had an abnormal study with the portable ultrasound device. There was a high rate of false-positive examinations, but approximately 17% of patients without a clinical indication for echocardiography had an important cardiac abnormality detected, including 10% with unsuspected left ventricular systolic dysfunction.

CONCLUSIONS

Many patients on a general medical hospital ward have unsuspected, clinically important cardiac findings such as left ventricular dysfunction that can be screened for by physicians with training in echocardiography using small portable ultrasound devices.

Physician-performed point-of-care echocardiography using a laptop platform compared with physical examination in the cardiovascular patient

OBJECTIVES

The purpose of this study was to compare the results of physical examinations (PEs) performed by board-certified cardiologists with the results of point-of-care (POC) echocardiography in a group of patients with cardiovascular disease.

BACKGROUND

Although cardiovascular PE is crucial in the evaluation of patients with suspected heart disease, the skills required to diagnose abnormal cardiovascular findings have been declining. Echocardiography is a powerful noninvasive cardiovascular diagnostic tool; however, echocardiographic evaluation of patients is not performed at the time of patient encounter (POC echocardiography), beacuse current platforms are cumbersome and expensive for individual physician use. The development of miniaturized echocardiographic equipment has the potential to overcome some of these limitations.

METHODS

Thirty-six subjects had a complete cardiovascular examination by four board-certified cardiologists. The physicians subsequently imaged each patient using a miniaturized echocardiographic platform. The yield of PE and POC echocardiography were compared using a complete echocardiographic study as the gold standard, performed on an upper-end platform.

RESULTS

Cardiac examination failed to detect 59% of the overall cardiovascular findings. Physician-performed echocardiography with the prototype device missed 29% of the overall cardiovascular pathology. When considering only the major cardiovascular findings, the cardiologists' PEs still failed to correctly detect 43%. Point-of-care echocardiography reduced this to 21% without significant interphysician variation.

CONCLUSIONS

Point-of-care echocardiography using a miniaturized echocardiographic platform substantially improved the detection of important cardiovascular pathology compared with PE. Use of this device by a cardiovascular specialist with training in echocardiography as a routine adjunct to PE appears to be useful.

Echocardiography in the evaluation of systolic murmurs of unknown cause

PURPOSE

Systolic murmurs are common, and it is important to know whether physical examination can reliably determine their cause. Therefore, we prospectively assessed the diagnostic accuracy of a cardiac examination in patients without previous echocardiography who were referred for evaluation of a systolic murmur.

SUBJECTS AND METHODS

In 100 consecutive adults (mean [+/- SD] age of 58 +/- 22 years) who were referred for a systolic murmur of unknown cause, the diagnostic accuracy of the cardiac examination by cardiologists (without provision of clinical history, electrocardiogram, or chest radiograph) was compared with the results of echocardiography.

RESULTS

The echocardiographic findings included a normal examination (functional murmur) in 21 patients, aortic stenosis in 29 patients, mitral regurgitation in 30 patients, left or right intraventricular pressure gradient in 11 patients, mitral valve prolapse in 11 patients, ventricular septal defect in 4 patients, hypertrophic obstructive cardiomyopathy in 3 patients, and associated aortic regurgitation in 28 patients. In 28 (35%) of the 79 patients with organic heart disease, more than one abnormality was found; combined aortic and mitral valve disease was the most frequent combination (n = 22). The sensitivity of the cardiac examination was acceptable for detecting ventricular septal defect (100% [4 of 4]), isolated mitral regurgitation (88% [26 of 36]), aortic stenosis (71% [21 of 29]), and a functional murmur (67% [14 of 21]), but not for intraventricular pressure gradients (18% [2 of 11]), aortic regurgitation (21% [6 of 28]), combined aortic and mitral valve disease (55% [6 of 11]), and mitral valve prolapse (55% [12 of 22]). In 6 patients, the degree of aortic stenosis was misjudged on the clinical examination, mainly because of a severely diminished left ventricular ejection fraction. Significant heart disease was missed completely in only 2 patients.

CONCLUSION

In adults with a systolic murmur of unknown cause, a functional murmur can usually be distinguished from an organic murmur. However, the ability of the cardiac examination to assess the exact cause of the murmur is limited, especially if more than one lesion is present. Thus, echocardiography should be performed in patients with systolic murmurs of unknown cause who are suspected of having significant heart disease.

Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects

To determine the accuracy of the cardiovascular physical examination for the diagnosis of asymptomatic valvular heart disease (VHD), we prospectively studied 143 subjects, 68 apparent normal subjects and 75 patients with diseases known to produce VHD. All subjects underwent a complete physical examination with dynamic cardiac auscultation by a physician blinded to clinical data and compared with the results of transesophageal color Doppler echocardiography (TEE). By TEE, 33 subjects (23%), and by physical examination, 25 subjects (17%) had at least 1 form of VHD. Despite a high frequency of mild valve abnormalities and a 31% prevalence of functional murmurs, the physical examination showed a sensitivity of 70%, a specificity of 98% (confidence interval = 0.51 to 0.84, and 0.94 to 0.99, respectively), and a positive and negative predictive value of 92% for the diagnosis of VHD. Only 2 of the 10 patients with VHD by TEE, but not by physical examination, had clinically important VHD. We conclude that the physical examination is a sensitive and highly specific method of screening for VHD in subjects without cardiac symptoms. Therefore, its use should be encouraged rather than the routine application of echocardiography.