Exercise-induced Wall Motion Abnormalities Research Articles

Prognostic relevance of exercise testing in hypertrophic cardiomyopathy. A systematic review

BackgroundCardiopulmonary exercise test (CPET) is indicated as part of the assessment in hypertrophic cardiomyopathy (HCM) patients and stress echocardiography is often used to assess symptoms. However, the role of exercise testing for prognostic stratification in HCM is still not established. AimsTo systematically review the evidence on the role of exercise testing for prognostic stratification in hypertrophic cardiomyopathy. MethodsA systematic review was conducted for eligible publications, between 2010 and 2020, that included evaluation of outcomes and prognosis. In these studies, patients underwent exercise echocardiography and/or cardiopulmonary exercise testing, performed according to predefined protocols. Diverse parameters were assessed in order to determine which were relevant for the prognosis. Analyzed outcomes included death from any cause, sudden cardiac death (SCD) and equivalents, cardiovascular death, heart failure requiring hospitalization or progression to New York Heart Association classes III or IV, cardiac transplantation, non-sustained ventricular tachycardia, stroke, myocardial infarction and invasive septal reduction therapy. ResultsEighteen publications were included, corresponding to a total of 7525 patients. The mean follow-up period varied between 1 and 8 years. The main findings of these studies revealed that the major predictors of outcomes were abnormal heart rate recovery, abnormal blood pressure response exercise induced wall motion abnormalities, lower peak VO2, higher VE/VCO2, and pulmonary hypertension/exercise-induced pulmonary hypertension. ConclusionAlthough most studies concluded that exercise test results are useful to determine prognosis in HCM, further investigation is needed regarding whether it adds independent value to the current risk stratification strategies.

Reversible exercise-induced left ventricular dysfunction in symptomatic patients with previous Takotsubo syndrome: insights from stress echocardiography.

Takotsubo syndrome (TTS) is usually associated with rapid and spontaneous recovery of left ventricular (LV) function. However, a proportion of patients may have persistent symptoms. This study aimed to determine the haemodynamic and LV contractile responses to exercise in these patients. Thirty symptomatic TTS patients referred for exercise echocardiography, a median of 15 months following the index TTS episode, were matched with 30 controls with normal exercise echocardiography. Beta-blockers were withheld prior to the test. LV volumes, ejection fraction (EF) and wall motion score index (WMSI), were measured at rest and stress. The TTS cohort were Caucasian women with mean age of 64.6 ± 7.4 years and similar coronary risk factor profile and EF to controls. Resting systolic blood pressure (SBP), LV end-diastolic volume, wall stress, and right ventricular fractional area change were higher in TTS patients compared with controls. Stress echo data showed similar exercise time, peak heart rate, and peak SBP in TTS patients vs. controls, but TTS patients had higher LV volumes, lower exercise LVEF (70 ± 10% vs. 78 ± 7%; P = 0.001), ΔLVEF (4 ± 8% vs. 12 ± 5%; P < 0.001), and WMSI (1.4 ± 0.4 vs. 1 ± 0; P < 0.001) compared with controls. Twenty TTS patients had clear exercise-induced wall motion abnormalities, mainly involving the apex or more globally, with a mean ΔLVEF of 1% compared with 12% in controls. Among the other 10 TTS patients, the ΔLVEF was 10%. Symptomatic patients with previous TTS have a blunted contractile response to exercise. The therapeutic and prognostic implications of these findings need further investigation.

Impaired global longitudinal strain in elderly patients with preserved ejection fraction is associated with raised post-exercise left ventricular filling pressure.

The purpose of this study was to evaluate whether impaired resting global longitudinal strain (GLS) in elderly patients with preserved left ventricular (LV) ejection fraction (EF) is associated with raised post-exercise LV filling pressure estimated by the ratio of early diastolic transmitral flow velocity to annulus velocity (E/e'). Seventy elderly patients (age = 74 ± 6years, male 40 patients) who underwent treadmill stress echocardiography were studied. All patients had normal sinus rhythm, normal LV wall motion at rest, and had preserved LVEF ≥ 50%. Patients with exercise induced wall motion abnormality were not included. GLS at rest was measured using automated functional imaging. Twenty-four of the 70 patients had raised post-exercise LV filling pressure indicated by septal E/e' ≥ 15.0. Patients with raised post-exercise LV filling pressure had smaller resting GLS than that in patients without it (-16.9 ± 1.8 vs. -19.6 ± 2.5%, respectively, p < 0.0001). Downward stepwise multivariate logistic regression analysis demonstrated that resting GLS was one of independent predictors of raised post-exercise E/e'. Receiver operating characteristic (ROC) curve analysis had demonstrated that optimal cutoff point for resting GLS to predict raised post-exercise E/e' was -17.8% (sensitivity 83.3%, specificity 80.4%, respectively), and the area under the ROC curve was 0.820. In elderly patients with preserved LVEF and without obvious myocardial ischemia, impaired resting GLS at rest is associated with raised post-exercise LV filling pressure estimated by E/e' ≥ 15.0.

P1497Reversible exercise-induced left ventricular dysfunction in symptomatic patients with previous Takotsubo syndrome - Insights from exercise echocardiography

Abstract Introduction Takotsubo syndrome (TTS) is an acute heart failure syndrome usually associated with rapid and spontaneous recovery of left ventricular (LV) function. However, approximately 10% of patients have persistent symptoms and seek further medical advice. Purpose To determine the cardiovascular haemodynamic and LV contractile response to exercise in these TTS survivors with ongoing symptoms. Methods This was a case-control study of 20 symptomatic patients with previous TTS referred for treadmill exercise echocardiography (EE), and 20 age-, sex- and ethnicity-matched control subjects with normal treadmill EE. Among the TTS group, EE was performed at a median of 8 months (mean 17±21 months) following the index event. Demographic characteristics, resting and EE data were collected. LV ejection fraction (EF) was measured at rest and peak stress. Global longitudinal and circumferential strain (GLS, GCS) were measured at rest. Results All 20 TTS patients were Caucasian postmenopausal females (mean age 63.5±6.6 years). There were no significant differences in body mass index (BMI), resting heart rate (HR) and the prevalence of cardiovascular risk factors compared to controls. Resting systolic and diastolic blood pressure (SBP, DBP) were higher in TTS patients (144±17 mmHg versus 128±18 mmHg, and 81±10 mmHg versus 74±9 mmHg, respectively). A comparative analysis of the resting and stress echo data is given in Table 1. The stress echo data showed similar exercise time and peak HR, but higher peak SBP in TTS patients. TTS patients had blunted contractile response to exercise with lower peak LVEF, ΔLVEF (exercise minus resting EF) and peak wall motion score index (WMSI) compared to controls. Among the 20 TTS patients, 12 had exercise-induced wall motion abnormalities: 6 involved the apical segments and 6 developed global dysfunction. In these 12 patients, the mean ΔLVEF was reduced (4%). In the other 8 patients, the ΔLVEF was 16% and pooled the TTS cohort had blunted contractile response with exercise compared to controls (ΔLVEF 8% vs. 19% in the control group, p=0.001). Table 1 Conclusions Our study shows that symptomatic patients with previous TTS have a blunted contractile response to exercise manifest as reversible apical or global LV dysfunction. These findings might indicate the need for treatment. Further systematic investigation of the therapeutic and prognostic implications of this reversible exercise-induced myocardial dysfunction is needed.

Usefulness of carotid ultrasonography in the diagnosis of coronary artery disease in patients undergoing exercise echocardiography

BackgroundRelationship between carotid and coronary artery disease (CAD) in patients undergoing invasive and non-invasive test is unclear. The aim of the study is to evaluate whether carotid disease is associated with CAD in patients submitted to exercise echocardiography (EE) and if it improves the EE ability to predict CAD.MethodsWe retrospectively studied 156 subjects without previous vascular disease who underwent EE, carotid ultrasonography and coronary angiography between 2002 and 2013. Positive EE was defined as exercise induced wall motion abnormalities, carotid disease according to Manheim and American Society of Echocardiography Consensus and significant CAD as stenosis ≥50%.ResultsEighty-nine (57.1%) subjects had significant CAD. Factors associated with CAD in multivariate analysis were fasting plasma glucose (odds ratio [OR] 1.02, p = 0.031), pre-test probability of CAD > 65% (OR 3.71, p < 0.001), positive EE (OR 10.51, p < 0.001) and carotid plaque (CP) presence (OR 2.95, p = 0.013). There was neither statistical significant difference in area under the curve after addition of CP to EE results (0.77 versus 0.81, p = 0.525) nor sensitivity, specificity, predictive values or efficiency. CP presence reclassified as very high-risk according to Systematic COronary Risk Evaluation 13 patients (34.2%) with negative EE and 22 (33.3%) without CAD.ConclusionCP is associated with CAD in patients undergoing EE, however its addition to EE does not improve CAD prediction, probably due to insufficient statistical power. CP reclassified one third of patients to very high-risk category despite negative EE or CAD absence, these subjects benefit from aggressive primary prevention interventions.

Low diastolic wall strain is associated with raised post-exercise E/E' ratio in elderly patients without obvious myocardial ischemia.

It has been reported that the diastolic wall strain (DWS) inversely correlates with the myocardial stiffness constant. The ratio of early diastolic transmitral flow velocity to annulus velocity (E/E') correlates with the left ventricular (LV) filling pressure. Increased LV wall stiffness is thought be associated with increased LV filling pressure after exercise. The purpose of this study was to evaluate the correlation between the DWS and post-exercise E/E' in elderly patients without obvious myocardial ischemia. Fifty-eight elderly patients (age=74±6years) who underwent treadmill stress echocardiography were studied. All patients had normal LV wall motion at rest, and patients with exercise-induced wall motion abnormality were excluded. The DWS was calculated as follows: DWS=(PWTs-PWTd)/PWTs, where PWTs is the LV posterior wall thickness at end-systole and PWTd is that at end-diastole. As previously reported, DWS≤0.33 was defined as low DWS and E/E' ≥15.0 was defined as a marker of increased LV filling pressure. Eighteen patients had low DWS. Patients with low DWS had greater post-exercise E/E' (17.9±3.2 vs. 12.8±3.3, p<0.0001). The DWS was inversely and strongly correlated with post-exercise E/E' (r (2)=0.534, p<0.0001). Low DWS predicted the development of raised post-exercise E/E' ≥15.0 with a positive predictive value of 94% and a negative predictive value of 85%. In elderly patients without obvious myocardial ischemia, the DWS correlates strongly and inversely with post-exercise E/E'. Patients with low DWS were likely to develop raised E/E' after exercise.

Head-to-Head Comparison of Peak Upright Bicycle and Post-Treadmill Echocardiography in Detecting Coronary Artery Disease: A Randomized, Single-Blind Crossover Study

Post-treadmill digital echocardiography (post-TME) is the most widely used form of exercise echocardiography, but ischemia can rapidly resolve in the postexercise period; peak upright bicycle digital echocardiography (UBE) has the advantage of providing images at peak exercise that reflect normal physiology. However, the comparative accuracy of the two methods in detecting ischemia in the same patients is unknown. To compare the relative diagnostic value of peak UBE and post-TME in detecting coronary artery disease, both tests were performed in 86 consecutive patients undergoing coronary angiography. Eighty-six patients referred for evaluation of coronary disease underwent peak UBE (starting at 25W, with 25-W increments every 3 min) and post-TME (Bruce protocol) in a random sequence. Digitized images of peak UBE and post-TME were interpreted in a random and blinded fashion. More transient wall motion abnormalities were detected with peak UBE than post-TME (55 vs 42, P<.001), and such exercise-induced wall motion abnormalities were more extensive (5.5 ± 3.0 vs 3.4 ± 2.1 dyskinetic segments, P < .001) and more severe (regional wall motion score index, 2.7 ± 0.5 vs 2.5 ± 0.5; P= .003). By angiography, 59 patients had coronary artery disease (a coronary stenosis of ≥50% diameter narrowing); the sensitivity of peak UBE for detecting coronary artery disease was greater than that of post-TME in the population as a whole (88% vs 66%, P < .01) and in the single-vessel subgroup (72% vs 44%, P < .05), with no worsening in specificity (89% vs 89%, P= NS). Peak UBE is more capable of detecting ischemia than post-TME, and this is achieved with no worsening of specificity. Thus, peak UBE should be preferred in patients able to perform bicycle exercise.

Left Ventricular Diastolic Function and Long-Term Outcomes in Patients With Normal Exercise Echocardiographic Findings

The objective of the present study was to determine whether diastolic dysfunction (DD) is associated with outcomes in the absence of myocardial ischemia. We studied 2,835 patients undergoing exercise echocardiography from January 2006 through December 2006 who had normal systolic function (ejection fraction ≥50%) and an absence of exercise-induced wall motion abnormalities. Diastolic function was graded as normal, mild DD, or moderate to severe DD. Medical records review and patient contact were undertaken to determine mortality, cardiovascular events (i.e., death, myocardial infarction, or stroke), incident heart failure (HF), and hospitalization. The mean ± SD age was 58.9 ± 12.8 years, and 54.0% were women. DD was present in 40.0% of the participants, with mild DD in 28.2% and moderate to severe DD in 11.8%. During a median follow-up of 4.4 years, 81 deaths and 114 cardiovascular events occurred, and DD was associated with greater rates of mortality, cardiovascular events, and HF events or hospitalizations (all p <0.001). On multivariate analysis, mild or moderate to severe DD (referent, normal function) was associated with HF or hospitalization (hazard ratio 1.45, 95% confidence interval 1.18 to 1.78, p <0.001 for mild DD; hazard ratio 1.75, 95% confidence interval 1.37 to 2.24, p<0.001 for moderate to severe DD) but was not independently associated with death or cardiovascular events. The diastolic index of filling pressure (E/e') was independently associated with mortality, cardiovascular events, and HF or hospitalization. In conclusion, among patients without demonstrable myocardial ischemia, left ventricular DD was associated with greater event rates during long-term follow up but did not independently predict hard end points other than HF or hospitalization. E/e' was independently associated with the clinical outcomes and might be an important echocardiographically derived parameter to identify in patients undergoing exercise echocardiography.

Exercise-induced torsional dyssynchrony relates to impaired functional capacity in patients with heart failure and normal ejection fraction

BackgroundLeft ventricular (LV) systole and diastole are intimately dependent on myocardial torsion, which involves coupling between myocardial rotation (twisting in systole and untwisting in diastole) and longitudinal motion. Heart failure...

Diastolic Electromechanical Coupling

Background— Electromechanical coupling, a well-described phenomenon in systolic dysfunction, has not been well studied in diastole. We hypothesized that the ECG T-peak to T-end (TpTe) interval, representing transmural dispersion of repolarization, is associated with echocardiographic markers of diastolic dysfunction (DD). Methods and Results— We performed a prospective, cross-sectional study of the association between TpTe and markers of DD in 84 consecutive, unselected patients referred for exercise echocardiography. We systematically measured TpTe on the resting ECG, and we performed comprehensive assessment of DD at rest and at peak stress. ECGs and echocardiograms were analyzed independently, blinded to each other and to all clinical data. By univariable analysis, increased TpTe was associated with older age, increased E/e’ ratio, and DD ( P &lt;0.05 for all associations after correcting for multiple comparisons). Increased TpTe was inversely associated with reduced tissue Doppler e’ velocity, a marker of DD ( R = −0.66, P &lt;0.0001). This association persisted after adjusting for age, QTc, exercise-induced wall motion abnormalities, and left ventricular mass index (β= −0.41 [95% confidence interval, −0.70 to −0.12] cm/s per 10-ms increase in TpTe; P =0.006). Baseline TpTe was also independently associated with resting DD (adjusted odds ratio, 3.9 [95% confidence interval, 1.4–10.7]; P =0.009) and peak exercise E/e’ ratio ( P &lt;0.0001). Conclusions— Increased TpTe is associated with both resting and exercise-induced DD. Electromechanical coupling may represent a pathophysiologic link between electrical transmural dispersion of repolarization and abnormal myocardial relaxation, and may be a novel therapeutic target.

Detection of high-burden coronary artery disease by exercise-induced changes of the E/E’ ratio

To investigate whether exercise-induced changes of the E/E' average ratio can detect high-burden coronary artery disease (CAD) in patients with chest pain and normal left ventricular (LV) systolic function. The study population consisted of 359 patients admitted for chest pain (59.8 ± 9.8 years, 75% male). Patients underwent exercise echocardiography, scintigraphy and coronary angiography. The average of the lateral and septal ratios of early diastolic transmitral velocity to early diastolic tissue velocity (E/E') at baseline and immediately after exercise was calculated. Exercise induced wall motion abnormalities were also calculated. Coronary angiography showed flow limiting CAD in 238 patients (66%). The exercise-induced changes of E/E' average ratio had a sensitivity of 87.3% and a specificity of 75.2% for detection of flow limiting CAD, whereas myocardial scintigraphy showed 79.2% sensitivity and 80.1% specificity and exercise induced wall motion abnormalities had a sensitivity of 74.3% and a specificity of 66.9%. Likelihood ratio chi square showed an incremental value of the exercise-induced changes of E/E' average ratio over regional perfusion technique (from 121.37 to 194.15, P < 0.001) and over wall motion abnormalities (from 57.03 to 146.50, P < 0.001). The exercise-induced change of the E/E' average ratio detects flow limiting CAD in patients with chest pain and normal LV systolic function showing an incremental value over regional perfusion technique and wall motion abnormalities.

Effect of Atrial Fibrillation on Outcome in Patients With Known or Suspected Coronary Artery Disease Referred for Exercise Stress Testing

The association of atrial fibrillation (AF) with coronary artery disease (CAD) remains controversial. In addition, the relation of AF to myocardial ischemia and outcomes in patients with known or suspected CAD referred for exercise stress testing has been poorly explored. In this study, 17,100 patients aged > or = 50 years with known or suspected CAD who underwent exercise electrocardiography (n = 11,911) or exercise echocardiography (n = 5,189) were evaluated. End points were all-cause mortality, nonfatal myocardial infarction, and coronary revascularization. Overall, 619 patients presented with AF at the time of the tests. Patients with AF who had interpretable electrocardiograms had a lower likelihood of exercise-induced ischemic ST-segment abnormalities (adjusted odds ratio 0.51, 95% confidence interval 0.34 to 0.76, p = 0.001), and those with AF who underwent exercise echocardiography had a lower likelihood of new or worsening exercise-induced wall motion abnormalities (adjusted odds ratio 0.62, 95% confidence interval 0.44 to 0.87, p = 0.006). During a mean follow-up period of 6.5 + or - 3.9 years, 2,364 patients died, 1,311 had nonfatal myocardial infarctions, 1,615 underwent percutaneous coronary intervention, and 922 underwent coronary artery bypass surgery. The 10-year mortality rate was 43% in patients with AF compared to 19% in those without AF (p <0.001). In multivariate analysis, AF remained an independent predictor of all-cause mortality (adjusted hazard ratio 1.45, 95% confidence interval 1.20 to 1.76, p <0.001), but not of nonfatal myocardial infarction or coronary revascularization. In conclusion, despite being associated with an apparently lower likelihood of myocardial ischemia, AF was an independent predictor of all-cause mortality in patients with known or suspected CAD referred for exercise stress testing.

Prediction of Mortality and Major Cardiac Events by Exercise Echocardiography in Patients with Normal Exercise Electrocardiographic Testing: Bouzas-Mosquera A, Peterio J, Alvarez-Garcia N, et al. J Am Coll Cardiol 2009;53:1981–90

Given that exercise-induced wall motion abnormalities appear earlier in myocardial ischemia than ST-segment changes, this study evaluated the use of exercise echocardiography (EE) to predict outcomes in patients with known or suspected coronary artery disease (CAD) and normal exercise electrocardiogram (ECG) testing. The study examined 4004 patients with known or suspected CAD and ECG changes at rest who had no evidence of myocardial ischemia during exercise ECG testing. The investigators divided these 4004 patients into two groups: history of CAD and no history of CAD.

Detection of coronary artery disease using delayed strain imaging at 5min after the termination of exercise stress: Head to head comparison with conventional treadmill stress echocardiography

Prolongation of the time to peak strain (TPS) is a sensitive marker of myocardial ischemia. The purpose of this study was to evaluate whether delayed strain imaging obtained at 5 min after the termination of exercise stress can detect patients with significant coronary artery disease (CAD). A total of 45 patients who underwent treadmill stress echocardiography and coronary angiography were studied. Patients with abnormal wall motion at rest were excluded. Digital echocardiographic images were recorded at baseline and immediately after the termination of treadmill stress. Exercise-induced wall motion abnormality was considered as a marker of myocardial ischemia. Tissue velocity images were also recorded at baseline and 5 min after the termination of treadmill stress, and TPS was measured. TPS ratio was calculated as the ratio between TPS at delayed post-exercise and TPS at baseline. Coronary angiography revealed that 30 of the 45 patients had significant CAD > or =50% diameter stenosis. The receiver operating characteristics curve demonstrated that cut-off value of TPS ratio 1.10 provides best diagnostic accuracy for vessel-based detection of significant CAD. The sensitivity, specificity, and diagnostic accuracy of the conventional exercise stress echocardiography for detecting patients with CAD were 87%, 80%, and 84%, respectively. The sensitivity, specificity, and accuracy of delayed strain imaging for identifying patients with CAD were 93%, 73%, and 87%, respectively. Delayed strain imaging obtained at 5 min after the termination of exercise stress can accurately detect patients with significant CAD.

Increase in end-systolic volume after exercise independently predicts mortality in patients with coronary heart disease: data from the Heart and Soul Study

The predictive value of changes in global left ventricular (LV) size after exercise has not been studied. Left ventricular end-systolic volume (ESV) is a relatively load-independent echocardiographic marker of contractility that is easily measured. We investigated the role of the change in ESV at rest and after peak exercise on mortality among patients with stable coronary heart disease (CHD). We performed exercise treadmill testing with stress echocardiography in 934 ambulatory subjects with CHD. End-systolic volume was measured immediately before and after exercise using 2D echocardiography. We defined ESV reversal as an increase in ESV after exercise, and we examined the association of ESV reversal with all-cause mortality during a median follow-up of 3.92 years. Of the 934 participants, 199 (21%) had ESV reversal. At the end of follow-up, mortality was higher among participants with ESV reversal than those without (26 vs. 11%; P < 0.001). After adjustment for clinical covariates, ESV reversal remained predictive of all-cause mortality (HR 2.0; 95% CI 1.4-2.9; P = 0.001). The association of ESV reversal with mortality also persisted after adjustment for exercise-induced wall-motion abnormalities (HR 1.7; 95% CI 1.1-2.3, P = 0.006). To determine if the effect of ESV reversal was independent from other echocardiographic measurements, we created a separate model adjusting for resting LV ejection fraction, ESV, end-diastolic volume, and LV mass. End-systolic volume reversal was the only significant predictor of mortality in this model (HR 2.1, 95% CI 1.4-3.0, P < 0.001). End-systolic volume reversal is a novel parameter that independently predicts mortality in patients with CHD undergoing exercise treadmill echocardiography, even after adjustment for a wide range of clinical, echocardiographic, and treadmill exercise variables. Because measurement of ESV is simple, reproducible, and requires no additional imaging views, identification of ESV reversal during exercise echocardiography can provide useful complementary information for risk stratification.

Exercise-induced changes in E/E′ ratio in patients with suspected coronary artery disease

Ischemia affects the left ventricular (LV) diastolic function earlier than the systolic function. The ratio of the early diastolic transmitral velocity to the early diastolic tissue velocity (E/E') measured by tissue Doppler echocardiography allows a reliable assessment of the diastolic function. We investigated whether exercise-induced changes in E/E' ratio may help in the detection of coronary artery disease (CAD). The study population consisted of 114 patients undergoing coronary angiography. Patients with impaired LV ejection fraction, earlier myocardial infarction, arterial hypertension greater than stage I, or LV hypertrophy were excluded. Patients underwent a treadmill exercise test combined with an echocardiogram at baseline and within the first minute after exercise. Coronary angiography showed a stenosis more than 70% in 72 (63%) patients (CAD group), the remaining 42 formed the non-CAD group. The two groups did not differ regarding age, sex, LV dimensions, and function. At baseline, the E/E' lateral and septal ratios and their average did not differ between the two groups. The exercise-induced changes of the E/E' ratios were higher in the CAD group (change of E/E' average: 1.9+/-3.3 vs. -1.1+/-2.3, P<0.001). In the CAD group, 78% showed an exercise-induced increase of E/E' average compared with 24% in the non-CAD group (P<0.001). In multivariate analysis, the association between an increase of E/E' average and the presence of obstructive CAD was independent of traditional risk factors, exercise test result or exercise-induced wall motion abnormalities (odds ratio=8.1, P<0.001). Exercise-induced changes in E/E' ratio may offer significant assistance in the detection of CAD.

Prognosis of Patients with Good Exercise Capacity and Mildly Abnormal Exercise Echocardiography Results: Identification of an At-risk Subgroup

Patients with good exercise capacity and mildly abnormal exercise echocardiography results have a favorable overall prognosis. We sought to define subgroups that might be at higher risk. We examined outcomes of 868 patients (women, > or = 5 metabolic equivalents; men, > or = 7 metabolic equivalents) with mild rest- or exercise-induced wall-motion abnormalities and evaluated potential predictors of time to cardiac death or nonfatal myocardial infarction (MI). Mean age was 64 +/- 10 years; 477 patients (55%) were men. Mean follow-up was 3.1 +/- 1.5 years; cardiac event rate was 1.2% per person-year. A history of MI was the only significant predictor (risk ratio, 3.9; 95% confidence interval, 1.9-7.8; P = .0001), with 1-, 3-, and 5-year event-free survival of 98.5% +/- 1.1%, 92.6% +/- 2.6%, and 83.3% +/- 5.1%, respectively (event rate, 3.4%). Patients with a history of MI have a higher annual cardiac event rate and may benefit from reevaluation, whereas no history of MI connotes a favorable prognosis.

Screening for heart disease in diabetic subjects

The prevalence of left ventricular hypertrophy (LVH), coronary artery disease, and subclinical cardiomyopathy in diabetic patients without known cardiac disease is unclear. We sought the frequency of these findings to determine whether plasma brain natriuretic peptide (BNP) could be used as an alternative screening tool to identify subclinical LV dysfunction. Asymptomatic patients with diabetes mellitus without known cardiac disease (n = 101) underwent clinical evaluation, measurement of BNP, exercise stress testing, and detailed echocardiographic assessment. After exclusion of overt dysfunction or ischemia, subclinical myocardial function was sought on the basis of myocardial systolic (Sm) and diastolic velocity (Em). Association was sought between subclinical dysfunction and clinical, biochemical, exercise, and echocardiographic variables. RESULTS; Of 101 patients, 22 had LVH and 16 had ischemia evidenced by exercise-induced wall motion abnormalities. Only 4 patients had abnormal BNP levels; BNP was significantly increased in patients with LVH. After exclusion of LVH and coronary artery disease, subclinical cardiomyopathy was identified in 24 of 66 patients. Subclinical disease could not be predicted by BNP. Even after exclusion of asymptomatic ischemia and hypertrophy, subclinical systolic and diastolic dysfunction occurs in a significant number of patients with type 2 diabetes. However, screening approaches, including BNP, do not appear to be sufficiently sensitive to identify subclinical dysfunction, which requires sophisticated echocardiographic analysis.

Prognostic significance of the location of wall motion abnormalities during exercise echocardiography

ObjectivesOur aim was to determine whether location of wall motion abnormalities (WMAs) during exercise echocardiography provides independent prognostic value. BackgroundThe effect of the location of WMAs during stress echocardiography on prognostic outcome is unknown. MethodsWe studied 4,347 patients (mean age, 61 ± 12 years; 2,230 men) with known or suspected coronary artery disease by symptom-limited exercise echocardiography. An abnormal result was defined as resting or exercise-induced WMA. End points were cardiac death and nonfatal myocardial infarction (MI). ResultsThere were 133 cardiac events (54 cardiac deaths and 79 nonfatal MIs) during follow-up (median, three years). In a multiple-stepwise multivariate analysis model, clinical and exercise electrocardiography predictors of cardiac events were age, gender, hypertension, typical chest pain, previous MI, smoking, and resting ejection fraction. The percentage of ischemic segments at peak exercise provided additional information to the model (p = 0.0001). The presence of abnormalities in the left anterior descending (LAD) coronary artery distribution had an additional independent effect for the prediction of cardiac events (p = 0.001). Among patients with exercise echocardiographic abnormalities in a single vascular region, those with abnormalities in the left anterior descending coronary artery distribution had a higher event rate than patients with abnormalities elsewhere (3.2% vs. 2.1% at three years and 10.8% vs. 2.1% at five years; p = 0.009). ConclusionsExercise WMAs in the distribution of the LAD coronary artery are associated with an increased risk of cardiac death and nonfatal MI. This risk is independent of the resting ejection fraction and the extent of WMAs during exercise.

Usefulness of isometric handgrip during treadmill exercise stress echocardiography

Usefulness of isometric handgrip during treadmill exercise stress echocardiography