Aortic valve sclerosis and clinical outcomes: moving toward a definition.

The presence of aortic valve sclerosis has been suggested as a marker of increased cardiovascular risk, including increased mortality. However, it remains unclear whether aortic valve sclerosis is independently associated with risk or merely a marker of coexistent cardiovascular risk factors. Aortic valve sclerosis is usually diagnosed on transthoracic echocardiography, the most widely used imaging modality in observational and natural history studies of aortic valve disease. Defining aortic valve sclerosis has remained challenging due to the variable and qualitative nature of its description by ultrasound techniques. Importantly, artifacts common to ultrasound imaging and awareness of demographic and clinical history information may bias the diagnosis of aortic valve sclerosis. Because clinicians may alter treatment recommendations or follow-up based on echocardiographic reporting of aortic valve sclerosis, highlighting pitfalls of the subjective nature by which aortic valve sclerosis is identified and establishing diagnostic criteria are necessary. This review describes the diagnostic criteria for aortic valve sclerosis used in outcome studies, summarizes the epidemiological findings reporting the relationship between aortic valve sclerosis and clinical outcome, and proposes a definition of aortic valve sclerosis based on the literature.

Is the standard weight-based dosing of dobutamine for stress testing appropriate for patients of widely varying body mass index?

BACKGROUND: Although a gradual increase in heart rate (HR) during dobutamine stress testing (DST) is desired, few data exists regarding whether this is similarly achieved in patients of widely varying body mass index (BMI). Whether difference in BMI contributes to variation in the hemodynamic and symptomatic response to dobutamine is also unknown. METHODS: From prospectively acquired data of 2776 consecutive patients who underwent DST according to standard weight-based clinical protocol, we classified patients into 4 groups of BMI (kg/m( 2)): <25 (normal), 25 to 29.9 (overweight), 30 to 39.9 (obese), and ≥ 40 (severely obese) and compared the rate of increase of HR, mean blood pressure, and development of symptoms for the groups. RESULTS: Age was 68 + 12 years, 52% were men, BMI was 29.8 + 6.6 kg/m(2) (range 14.5-81.4), 198 (7%) had BMI ≥ 40, and target HR was achieved in 2433 (88%). The rate of increase in HR was similar for each group of BMI after adjustment for age, gender, baseline HR, negative chronotropic use, and atropine administration. The percentage of patients in each group who achieved target HR was similar and the percentage of target HR achieved at each stage of dobutamine was essentially equivalent. Blood pressure responses and development of symptoms were similar in the 4 groups of BMI. Independent predictors of failure to achieve target HR included age, diabetes mellitus, treatment with negative chronotropic medications, and baseline HR; BMI was not a predictor (odds ratio [OR] 0.98, P = .086). CONCLUSION: The current weight-based protocol of dobutamine dosing for DST results in similar increases in HR and blood pressure for patients of widely varying BMI.

Sex differences in morphology and outcomes of mitral valve prolapse.

BACKGROUND: Mitral valve prolapse is more common in women than in men, but men more often have surgery for severe regurgitation. OBJECTIVE: To compare morphology and outcomes of mitral valve prolapse in men and women. DESIGN: Retrospective cohort study. SETTING: The Mayo Clinic, Rochester, Minnesota. PATIENTS: 4461 women and 3768 men who received a diagnosis of mitral valve prolapse by echocardiography from 1989 to 1998 (896 Olmsted County residents and 7333 referred patients). MEASUREMENTS: Mitral prolapse characteristics (localization, leaflet thickening or flail, regurgitation), ventricular and atrial characteristics, cardiac surgery, and mortality. RESULTS: Compared with men, women had less posterior prolapse (22% vs. 31%), less flail (2% vs. 8%), more leaflet thickening (32% vs. 28%), and less frequent severe regurgitation (10% vs. 23%) (P<0.001 for all comparisons). Regardless of the severity of regurgitation, left ventricular and atrial diameters were smaller in women than in men but were larger in women after normalization to body surface area. Among patients with severe regurgitation, women were less likely than men to undergo cardiac valve surgery (52% vs. 60%; adjusted risk ratio, 0.79 [95% CI, 0.74 to 0.84]). At 15 years, women with no or mild mitral regurgitation had better odds of survival than men (87% vs. 77%; adjusted risk ratio, 0.82 [CI, 0.76 to 0.89]), but those with severe regurgitation had worse survival than men (60% vs. 68%; adjusted risk ratio, 1.13 [CI, 1.01 to 1.26]). The survival rate 10 years after surgery was similar in women and men (77% vs. 79%; P=0.14). Observations in Olmsted County patients and referred patients were similar. LIMITATION: Diagnoses were based on echocardiography, and clinical data at initial diagnosis, reason for index echocardiography, and cause of all deaths were lacking. CONCLUSION: Morphology and severity of mitral valve prolapse differ according to sex. Among patients with severe regurgitation, women have higher mortality and lower surgery rates than men.

Safety of exercise stress testing in patients with abnormal concentrations of serum potassium.

The objective of this study was to determine the safety of performing exercise stress testing in patients with abnormal serum potassium concentrations. Data were reviewed from 9,084 patients (mean age 63 +/- 12 years) referred for exercise echocardiography who had serum potassium measured <48 hours before the test were reviewed, and the occurrence of arrhythmias during stress testing was determined. Of 10,272 studies, 9,067 (88%) were in patients with normokalemia and 1,205 (12%) were in patients with abnormal serum potassium concentrations: 309 (26%) with hypokalemia (mean 3.4 +/- 0.16 mmol/L) and 896 (74%) with hyperkalemia (mean 5.1 +/- 0.19 mmol/L). Ventricular and supraventricular ectopy were common during exercise. Only 1 patient (potassium 4.9 mmol/L) had sustained ventricular tachycardia; all other episodes were nonsustained. Although ventricular and supraventricular ectopy are common during exercise testing, life-threatening arrhythmias are not. Exercise testing is generally safe despite mild to moderate hypokalemia or hyperkalemia.

Prognostic significance of ST-segment elevation during dobutamine stress echocardiography.

BACKGROUND: Limited data are available concerning the significance of ST-segment elevation during dobutamine stress echocardiography (DSE). The purpose of this study was to assess the prognostic significance of new ST-segment elevation during DSE and its relationship to angiographic severity of coronary artery disease (CAD). METHODS: From 4240 consecutive patients who had DSE, we identified 134 (3%) patients with new stress-induced ST-segment elevation > or =1 mm in at least two contiguous electrocardiographic leads. Significant CAD was considered as > or =50% diameter obstruction by angiography. Follow-up was obtained for cardiac events. RESULTS: Age was 69 +/- 10 years; 84 (63%) were men. ST-segment elevation developed in the anterior leads in 55 (41%), inferior leads in 100 (75%), and lateral leads in 54 (40%); 56 (42%) had ST elevation in more than one region. Dobutamine stress echocardiography was abnormal in all patients; 115 (86%) had ischemia. Coronary angiography was obtained in 69 (51%) patients. Stenosis was > or =70% diameter in 68 (99%) patients and multivessel in 53 (77%). Follow-up (2.6 +/- 2.8 years) was obtained in all 134 patients. Events occurred in 103 (77%) patients, including death in 53, coronary revascularization in 33, myocardial infarction in 12, and unstable angina in 5. Event-free survival was 55% at 2 years, 38% at 4 years, and 28% at 5 years. CONCLUSIONS: Patients with stress-induced ST-segment elevation during DSE commonly have severe CAD and are at high risk for events during follow-up. These patients should be considered for coronary angiography.

Echocardiography or auscultation? How to evaluate systolic murmurs.

OBJECTIVE: To compare cardiac physical examination with echocardiography for evaluating systolic murmurs. QUALITY OF EVIDENCE: Three databases were searched for studies comparing echocardiography and auscultation as to sensitivity and diagnostic accuracy: MEDLINE (Ovid Online), EMBASE, and Current Contexts. The quality of reported data is lowered by subjective interpretation of results of both cardiac physical examination and echocardiography, especially Doppler colour flow imaging. MAIN MESSAGE: In adults, functional systolic murmurs can usually be distinguished from organic murmurs. Pathologic murmurs frequently have one or more associated clinical abnormalities. If a clinician determines a murmur is benign, results of echocardiography are very likely to be normal, especially in young and middle-aged adults. According to current guidelines, echocardiography should not be ordered for "innocent" systolic murmurs in patients who are asymptomatic and have otherwise normal findings on examination. If patients with functional systolic murmurs could be identified and not routinely referred for echocardiography, great cost savings could be realized. CONCLUSION: Echocardiography is not required for all patients with systolic murmurs and should not replace cardiac physical examination.

Clinical profile of autosomal dominant polycystic liver disease.

Most reports on the natural history, manifestations, and treatment of polycystic liver disease are based on the disease as it manifests in patients with autosomal dominant polycystic kidney disease (ADPKD). The purpose of this study was to develop a clinical profile of isolated autosomal dominant polycystic liver disease (ADPLD) using nonaffected family members as controls. The study included 146 probands, known affected relatives, and first-degree relatives of affected individuals. Participants underwent a formalized medical history interview and physical examination, ultrasonographic examination of the liver and kidneys, magnetic resonance angiography of the brain, and echocardiography. Thirty-eight of the 49 individuals diagnosed with polycystic liver disease before participation in the study were or had been symptomatic. Of 97 previously undiagnosed at-risk individuals, 23 were affected, 39 were unaffected, and 35 were indeterminate. Compared with patients with a negative or indeterminate diagnosis, those with polycystic liver disease had slightly higher levels of serum alkaline phosphatase and total bilirubin and lower levels of total cholesterol and triglycerides. Female patients had a significantly higher mean cyst score than male patients. The cysts were found to arise from the dilatation of biliary microhamartomas and from peribiliary glands. Structural mitral leaflet abnormalities were detected more frequently in affected than in indeterminate or nonaffected individuals. A vascular phenotype was detected in 5.6% of the patients with isolated ADPLD diagnosed clinically and/or by linkage analysis but in none of the unaffected patients. In conclusion, isolated ADPLD is underdiagnosed and genetically distinct from polycystic liver disease associated with ADPKD but with similar pathogenesis, manifestations, and management.

Natural history of asymptomatic mitral valve prolapse in the community.

BACKGROUND: The outcome of mitral valve prolapse (MVP) is controversial, with marked discrepancies in reported complication rates. METHODS AND RESULTS: We conducted a community study of all Olmsted County, Minn, residents first diagnosed with asymptomatic MVP between 1989 and 1998 (N=833). Diagnosis, motivated by auscultatory findings (n=557) or incidental (n=276), was always confirmed by echocardiography with the use of current criteria. End points analyzed during 4581 person-years of follow-up were mortality (n=96, 19+/-2% at 10 years), cardiovascular morbidity (n=171), and MVP-related events (n=109, 20+/-2% at 10 years). The most frequent primary risk factors for cardiovascular mortality were mitral regurgitation from moderate to severe (P=0.002, n=131) and, less frequently, ejection fraction <50% (P=0.003, n=31). Secondary risk factors independently predictive of cardiovascular morbidity were slight mitral regurgitation, left atrium > or =40 mm, flail leaflet, atrial fibrillation, and age > or =50 years (all P<0.01). Patients with only 0 or 1 secondary risk factor (n=430) had excellent outcome, with 10-year mortality of 5+/-2% (P=0.17 versus expected), cardiovascular morbidity of 0.5%/y, and MVP-related events of 0.2%/y. Patients with > or =2 secondary risk factors (n=250) had mortality similar to expected (P=0.20) but high cardiovascular morbidity (6.2%/y, P<0.01) and notable MVP-related events (1.7%/y, P<0.01). Patients with primary risk factors (n=153) showed excess 10-year mortality (45+/-9%, P=0.01 versus expected), high morbidity (18.5%/y, P<0.01), and high MVP-related events (15%/y, P<0.01). CONCLUSIONS: Natural history of asymptomatic MVP in the community is widely heterogeneous and may be severe. Clinical and echocardiographic characteristics allow separation of the majority of patients with excellent prognosis from subsets of patients displaying, during follow-up, high morbidity or even excess mortality as direct a consequence of MVP.

Hypertensive response to exercise: a potential cause for new wall motion abnormality in the absence of coronary artery disease.

OBJECTIVES: We sought to characterize patients with a hypertensive response during exercise echocardiography and its effect on results of the test. BACKGROUND: A hypertensive response to exercise has been shown to cause false-positive results in perfusion imaging, radionuclide angiography and exercise electrocardiography, but its influence on exercise echocardiography has not been reported. METHODS: We identified 548 of 6,686 patients who had coronary angiography within four weeks after exercise echocardiography from 1992 through 1996. Echocardiographic results from 132 patients (24%) with a hypertensive response to exercise, defined as systolic blood pressure (SBP) >220 mm Hg for men and SBP >190 mm Hg for women or as an increase in diastolic blood pressure (DBP) >10 mm Hg or DBP >90 mm Hg during exercise echocardiography, were compared with those from 416 patients without a hypertensive response. RESULTS: Of 132 patients with a hypertensive response to exercise, 108 patients had exercise echocardiographic results positive for ischemia. Of these patients, 24 (22%) were found to have no significant coronary artery disease (CAD). In contrast, of 320 patients with positive exercise echocardiographic results without a hypertensive response, 39 (12%) patients did not have significant CAD. Among the false-positive results, new wall motion abnormalities were extensive in 15 of 24 (63%) hypertensive responders involving >25% of segments compared with 14 of 39 non-hypertensive responders (36%, p = 0.012). CONCLUSIONS: An excessive rise in blood pressure during exercise is associated with a greater likelihood of new or worsening abnormalities with exercise, which may be observed in the absence of angiographically significant coronary artery stenosis.