Long-term prognostic value of dobutamine stress echocardiography compared with myocardial perfusion scanning in patients unable to perform exercise tests

Cultural values influencing iTaukei women's discussion of family planning in the home

Pacific Sexual and reproductive health is influenced by cultural taboos and sensitivities. Although Pacific values are integral to family planning, open communication in the home is often difficult in the face of changing socio-cultural norms. This study explores the experiences of iTaukei Pacific women living in Fiji and Aotearoa New Zealand, and their discussion of family planning within the family setting. The study utilises talanoa methodology to understand women's realities and their navigation through shifting sexual and reproductive norms in both countries. The study found that although family may be seen as a place of 'truth' in which appropriate, culturally sensitive family planning communication should be available, this was challenged by cultural taboos or tabu which were persistent in family planning discussions. The study calls for greater reliance on holistic approaches to Pacific family planning perspectives and a greater examination of vā or the spaces within which Pacific women's experiences are negotiated and informed.

Cardiovascular imaging techniques for the assessment of coronary artery disease

Coronary artery disease continues to be the leading cause of morbidity and mortality worldwide. Recent clinical trials have not demonstrated any mortality benefit of percutaneous coronary intervention compared to medical management alone in the treatment of stable angina. While invasive coronary angiography remains the gold standard for diagnosing coronary artery disease, it comes with significant risks, including myocardial infarction, stroke and death. There have been significant advances in imaging techniques to diagnose coronary artery disease in haemodynamically stable patients. The latest National Institute for Health and Care Excellence and European College of Cardiology guidelines emphasise the importance of using these imaging techniques first to inform diagnosis. This review discusses these guidelines and imaging techniques, alongside their benefits and drawbacks.

Phase analysis single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) detects dyssynchrony in myocardial scar and increases specificity of MPI

BACKGROUND

Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is commonly used to assess patients with cardiovascular disease. However, in certain scenarios, it may have limited specificity in the identification of hemodynamically significant coronary artery disease (e.g., false positive), potentially resulting in additional unnecessary testing and treatment. Phase analysis (PA) is an emerging, highly reproducible quantitative technology that can differentiate normal myocardial activation (synchrony) from myocardial scar (dyssynchrony). The objective of this study is to determine if PA can improve the specificity SPECT MPI.

METHODS

An initial cohort of 340 patients (derivation cohort), referred for SPECT-MPI, was prospectively enrolled. Resting MPI studies were assessed for resting perfusion defects (scar). These were utilized as the reference standard for scar. Subsequently, we collected a second independent validation cohort of 138 patients and tested the potential of PA to reclassify patients for the diagnosis of "scar" or "no scar." Patients were assigned to three categories depending upon their pre-test probability of scar based on multiple clinical and imaging parameters: ≤ 10% (no scar), 11-74% (indeterminate), and ≥ 75% (scar). The ability of PA variables to reclassify patients with scar to a higher group and those without scar to a lower group was then determined using the net reclassification index (NRI).

RESULTS

Entropy (≥ 59%) was independently associated with scar in both patient cohorts with an odds ratio greater than five. Furthermore, when added to multiple clinical/imaging variables, the use of entropy significantly improved the area under the curve for assessment of scar (0.67 vs. 0.59, p = 0.04). The use of entropy correctly reclassified 24% of patients without scar, by clinical model, to a lower risk category (as determined by pre-test probability) with an overall NRI of 18% in this validation cohort.

DISCUSSION

The use of PA entropy can improve the specificity of SPECT MPI and may serve as a useful adjunctive tool to the interpreting physician. The current study determined the optimal PA parameters to detect scar (derivation cohort) and applied these parameters to a second, independent, patient group and noted that entropy (≥ 59%) was independently associated with scar in both patient cohorts. Therefore, PA, which requires no additional imaging time or radiation, enhances the diagnostic capabilities of SPECT MPI.

CONCLUSION

The use of PA entropy significantly improved the specificity of SPECT MPI and could influence the labeling of a patient as having or not having myocardial scar and thereby may influence not only diagnostic reporting but also potentially prognostic determination and therapeutic decision-making.

Cardiac stress imaging for the prediction of very long-term outcomes: Dobutamine stress echocardiography or dobutamine 99mTc-sestamibi SPECT?

BACKGROUND

Both dobutamine stress echocardiography (DSE) and myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) are frequently used for cardiac risk stratification. The long-term relative prognostic value of these modalities has not been studied. Therefore, this study evaluated the long-term prognostic value of DSE compared to MPI in patients unable to perform exercise testing.

METHODS

This prospective, single center study included 301 patients (mean age 59 ± 12 years, 56% men) unable to perform exercise tests who underwent DSE and dobutamine stress 99mTc-sestamibi MPI. End points during follow-up were all-cause mortality, cardiac mortality, and nonfatal myocardial infarction (MI). Univariable and multivariable Cox proportional hazards regression models were used to identify independent predictors of outcome. The probability of survival was calculated using the Kaplan-Meier method.

RESULTS

A total of 182 patients (60%) had an abnormal DSE and 198 (66%) patients had an abnormal MPI. The agreement between DSE and MPI was 82% (κ = 0.62). During a median follow-up of 14 years (range 5-18), 172 deaths (57%) occurred, of which 72 (24%) were due to cardiac causes. Nonfatal MI occurred in 46 patients (15%). The multivariable analysis demonstrated that an abnormal DSE was a significant predictor of cardiac mortality (HR 2.35, 95% CI [1.17-4.73]) and hard cardiac events (HR 2.11, 95% CI [1.25-3.57]). Also, an abnormal MPI result was a significant predictor of cardiac mortality (HR 3.03, 95% CI [1.33-6.95]) and hard cardiac events (HR 2.06, 95% CI [1.12-3.79]).

CONCLUSIONS

DSE and MPI are comparable in predicting long-term cardiac mortality and hard cardiac events in patients unable to perform exercise testing.

Lower diastolic wall strain is associated with coronary revascularization in patients with stable angina

Background

Left ventricular (LV) diastolic dysfunction occurs earlier in the ischemic cascade than LV systolic dysfunction and electrocardiographic changes. Diastolic wall strain (DWS) has been proposed as a marker of LV diastolic stiffness. Therefore, the objectives of this study were to define the relationship between DWS and coronary revascularization and to evaluate other echocardiographic parameters in patients with stable angina who were undergoing coronary angiography (CAG).

Methods

Four hundred forty patients [mean age: 61 ± 10; 249 (57%) men] undergoing CAG and with normal left ventricular systolic function without regional wall motion abnormalities were enrolled. Among them, 128 (29%) patients underwent revascularization (percutaneous intervention: 117, bypass surgery: 11). All patients underwent echocardiography before CAG and the DWS was defined using posterior wall thickness (PWT) measurements from standard echocardiographic images [DWS = PWT(systole)-PWT(diastole)/PWT(systole)].

Results

Patients who underwent revascularization had a significantly lower DWS than those who did not (0.26 ± 0.08 vs. 0.38 ± 0.09, p < 0.001). Age was comparable between the two groups (61 ± 9 vs. 60 ± 11, p = 0.337), but the proportion of males was significantly higher among patients who underwent revascularization (69 vs. 52%, p = 0.001). The LV ejection fraction was similar but slightly decreased (60.9 ± 5.7 vs. 62.4 ± 6.2%, p = 0.019) and the E/E’ ratio was elevated (10.3 ± 4.0 vs. 9.0 ± 3.1, p < 0.001) among patients who underwent revascularization. In multiple regression analysis, lower DWS was an independent predictor of revascularization (cut-off value: 0.34; sensitivity: 89%; AUC: 0.870; SE: 0.025; p < 0.001).

Conclusion

DWS, a simple parameter that can be calculated from routine 2D echocardiography, is inversely associated with the presence of coronary artery disease and the need for revascularization.

Cardiac imaging to investigate suspected cardiac pain in the post-treadmill era

Symptomatic cardiovascular disease is one of the leading causes of hospital admissions in the UK; along with emergency attendances, over 100,000 patients are investigated using treadmill testing via rapid access chest pain clinics each year. With the introduction of new technologies, clinicians have a wide choice of investigations including nuclear perfusion scanning, dobutamine stress echocardiography, cardiac computed tomography and stress cardiac magnetic resonance imaging. These imaging modalities have their strengths and weaknesses, which depend not only on the pre-test likelihood of significant coronary artery disease but also the clinical characteristics of the patient. This article will review the differing imaging modalities, the patient experience, accuracy, prognostic data and future prospects for cardiac computed tomography and magnetic resonance imaging.

Bronchoconstriction in nonhuman primates: a species comparison

Bronchoconstriction is a characteristic symptom of various chronic obstructive respiratory diseases such as chronic obstructive pulmonary disease and asthma. Precision-cut lung slices (PCLS) are a suitable ex vivo model to study physiological mechanisms of bronchoconstriction in different species. In the present study, we established an ex vivo model of bronchoconstriction in nonhuman primates (NHPs). PCLS prepared from common marmosets, cynomolgus macaques, rhesus macaques, and anubis baboons were stimulated with increasing concentrations of representative bronchoconstrictors: methacholine, histamine, serotonin, leukotriene D₄ (LTD₄), U46619, and endothelin-1. Alterations in the airway caliber were measured and compared with previously published data from rodents, guinea pigs, and humans. Methacholine induced maximal airway constriction, varying between 74 and 88% in all NHP species, whereas serotonin was ineffective. Histamine induced maximal bronchoconstriction of 77 to 90% in rhesus macaques, cynomolgus macaques, and baboons and a lesser constriction of 53% in marmosets. LTD₄ was ineffective in marmosets and rhesus macaques but induced a maximum constriction of 44 to 49% in cynomolgus macaques and baboons. U46619 and endothelin-1 caused airway constriction in all NHP species, with maximum constrictions of 65 to 91% and 70 to 81%, respectively. In conclusion, PCLS from NHPs represent a valuable ex vivo model for studying bronchoconstriction. All NHPs respond to mediators relevant to human airway disorders such as methacholine, histamine, U46619, and endothelin-1 and are insensitive to the rodent mast cell product serotonin. Only PCLS from cynomolgus macaques and baboons, however, responded also to leukotrienes, suggesting that among all compared species, these two NHPs resemble the human airway mechanisms best.

Prediction of future cardiac events using myocardial perfusion SPECT: a middle-term follow-up study

BACKGROUND

Myocardial perfusion imaging (MPI) provides highly valuable information for risk stratification and determination of optimal clinical management. The goal of the present study was to assess the prognostic value of myocardial perfusion SPECT for the prediction of future cardiac events in Asian population.

METHODS

Five hundred and ten consecutive patients, who had undergone myocardial perfusion SPECT between 2005 and 2006, were prospectively followed-up. Patients' data were collected from recorded files. Follow-ups were performed by scripted telephone interviews by a physician blinded to the patients' MPI results and also from the hospital records. The total completed follow-ups consisted of 482 patients (follow-up rate, 94.5%).

RESULTS

Over the mean follow-up period of 434 ± 62 days, 14 out of 482 patients (2.9%) died from cardiac events. Also in 61 patients (12.7%), the clinical condition led to a cardiac intervention (Percutaneous coronary intervention or coronary artery bypass grafting). Those patients without cardiac events on follow-up (including cardiac death or myocardial infarction) were younger and with less severity of MPI abnormalities. Severe MPI abnormalities (Summed Stress Score > 13) were found in 42.9% of those with cardiac death, while in 17.2% of those with myocardial infarction. The rate of cardiac death had a direct relationship with the severity of scan abnormalities, however, the same association was not found between the severity of MPI abnormality and the rate of myocardial infarction.

CONCLUSION

MPI is a valuable tool for risk stratification and prediction of future fatal cardiac events in Asian population. The risk of cardiac death as a mid-term outcome of coronary artery disease increases significantly with severity of MPI abnormalities.

Long-term outcome of prophylactic coronary revascularization in cardiac high-risk patients undergoing major vascular surgery (from the randomized DECREASE-V Pilot Study)

Prophylactic coronary revascularization in vascular surgery patients with extensive coronary artery disease was not associated with an improved immediate postoperative outcome. However, the potential long-term benefit was unknown. This study was performed to assess the long-term benefit of prophylactic coronary revascularization in these patients. Of 1,880 patients scheduled for major vascular surgery, 430 had > or =3 risk factors (age >70 years, angina pectoris, myocardial infarction, heart failure, stroke, diabetes mellitus, and renal failure). All underwent cardiac testing using dobutamine echocardiography or nuclear stress imaging. Patients with extensive stress-induced ischemia (> or =5 segments or > or =3 walls) were randomly assigned to additional revascularization. In total, 101 patients showed extensive ischemia and were assigned to revascularization (n = 49) or no revascularization (n = 52). After 2.8 years, the overall survival rate was 64% for patients randomly assigned to no preoperative coronary revascularization versus 61% for patients assigned to preoperative coronary revascularization (hazard ratio [HR] 1.18, 95% confidence interval [CI] 0.63 to 2.19, p = 0.61). Rates for survival free of all-cause death, nonfatal myocardial infarction, and coronary revascularization were similar in both groups at 49% and 42% for patients allocated to medical treatment or coronary revascularization, respectively (HR 1.51, 95% CI 0.89 to 2.57, p = 0.13). Only 2 patients assigned to medical treatment required coronary revascularization during follow-up. Also, in patients who survived the first 30 days after surgery, there was no apparent benefit of revascularization on cardiac events (HR 1.35, 95% CI 0.72 to 2.52, p = 0.36). In conclusion, preoperative coronary revascularization in high-risk patients undergoing major vascular surgery was not associated with improved postoperative or long-term outcome compared with the best medical treatment.

Incidence and prognostic implication of unrecognized myocardial scar characterized by cardiac magnetic resonance in diabetic patients without clinical evidence of myocardial infarction

BACKGROUND

Silent myocardial infarctions (MIs) are prevalent among diabetic patients and inflict significant morbidity and mortality. Although late gadolinium enhancement (LGE) imaging by cardiac magnetic resonance (CMR) can provide sensitive characterization of myocardial scar, its prognostic significance in diabetic patients without any clinical evidence of MI is unknown.

METHODS AND RESULTS

We performed clinically indicated CMR imaging in 187 diabetic patients who were grouped by the absence (study group, n=109) or presence (control group, n=78) of clinical evidence of MI (clinical history of MI or Q waves on ECG). CMR imaging and follow-up were successful in 107 study patients (98%) and 74 control patients (95%). Cox regression analyses were performed to associate LGE with major adverse cardiovascular events (MACE), including death, acute MI, new congestive heart failure or unstable angina, stroke, and significant ventricular arrhythmias. LGE by CMR was present in 30 of 107 study patients (28%). At a median follow-up of 17 months, 38 of 107 patients (36%) experienced MACE, which included 18 deaths. Presence of LGE was associated with a >3-fold hazards increase for MACE and for death (hazard ratio, 3.71 and 3.61; P<0.001 and P=0.007, respectively). Adjusted to a model that combines patient age, sex, ST or T changes on ECG, and left ventricular end-systolic volume index, LGE maintained a >4-fold hazards increase for MACE (adjusted hazard ratio, 4.13; 95% confidence interval, 1.74 to 9.79; P=0.001). In addition, LGE provided significant prognostic value with MACE and with death adjusted to a diabetic-specific risk model for 5-year events. The presence of LGE was the strongest multivariable predictor of MACE and death by stepwise selection in the study patients.

CONCLUSIONS

CMR imaging can characterize occult myocardial scar consistent with MI in diabetic patients without clinical evidence of MI. This imaging finding demonstrates strong association with MACE and mortality hazards that is incremental to clinical, ECG, and left ventricular function combined.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

A clinical randomized trial to evaluate the safety of a noninvasive approach in high-risk patients undergoing major vascular surgery: the DECREASE-V Pilot Study

OBJECTIVES

The purpose of this research was to perform a feasibility study of prophylactic coronary revascularization in patients with preoperative extensive stress-induced ischemia.

BACKGROUND

Prophylactic coronary revascularization in vascular surgery patients with coronary artery disease does not improve postoperative outcome. If a beneficial effect is to be expected, then at least those with extensive coronary artery disease should benefit from this strategy.

METHODS

One thousand eight hundred eighty patients were screened, and those with > or =3 risk factors underwent cardiac testing using dobutamine echocardiography (17-segment model) or stress nuclear imaging (6-wall model). Those with extensive stress-induced ischemia (> or =5 segments or > or =3 walls) were randomly assigned for additional revascularization. All received beta-blockers aiming at a heart rate of 60 to 65 beats/min, and antiplatelet therapy was continued during surgery. The end points were the composite of all-cause death or myocardial infarction at 30 days and during 1-year follow-up.

RESULTS

Of 430 high-risk patients, 101 (23%) showed extensive ischemia and were randomly assigned to revascularization (n = 49) or no revascularization. Coronary angiography showed 2-vessel disease in 12 (24%), 3-vessel disease in 33 (67%), and left main in 4 (8%). Two patients died after revascularization, but before operation, because of a ruptured aneurysm. Revascularization did not improve 30-day outcome; the incidence of the composite end point was 43% versus 33% (odds ratio 1.4, 95% confidence interval 0.7 to 2.8; p = 0.30). Also, no benefit during 1-year follow-up was observed after coronary revascularization (49% vs. 44%, odds ratio 1.2, 95% confidence interval 0.7 to 2.3; p = 0.48).

CONCLUSIONS

In this randomized pilot study, designed to obtain efficacy and safety estimates, preoperative coronary revascularization in high-risk patients was not associated with an improved outcome.

Emergency cardiac imaging: state of the art

Multiple strategies and testing modalities are available to evaluate patients presenting to the emergency department with cardiac complaints. Many provide anatomic and prognostic information about coronary stenosis and long-term out-comes. Although nuclear and stress echo imaging have the ability to predict outcomes in patients in the emergency department population, the newer modalities of cardiac imaging (EBCT, MDCT,and CMR) continue to show promising results and may soon be incorporated into emergency department chest pain centers. Protocols can be developed within an institution to meet the needs of the patient population while minimizing risk and improving outcomes for all patients.

Noninvasive assessment of coronary artery disease in diabetic patients: The role of stress echocardiography

Diabetes mellitus is a frequently occurring disease, and its prognosis is essentially related to cardiac complications. Some have suggested that these patients should be considered as coronary artery disease (CAD)-equivalent and treated aggressively, accordingly. In addition, CAD in diabetes patients at the time of diagnosis is often more advanced, and is frequently associated with more extensive disease, a greater incidence of left ventricular dysfunction and higher rates of cardiac events. Unfortunately, the standard exercise treadmill stress test has important limitations, with a poor sensitivity for CAD detection if the patient has limited exercise capacity, which is the case for more than one-half of the diabetic patients in some series. The detection of regional wall motion abnormality with echocardiography permits the identification of the coronary territory involved. It can be used for CAD diagnosis, evaluation of myocardial viability, risk stratification following a myocardial infarction and assessment of preoperative risk before noncardiac surgery. The risk of CAD in patients with diabetes mellitus is reviewed, and the role of noninvasive testing with stress echocardiography in the diagnosis and risk stratification of these patients is discussed.

Pacemaker stress echocardiography predicts cardiac events in patients with permanent pacemaker

PURPOSE

Noninvasive pacemaker stress echocardiography is a newly introduced method for the diagnosis of coronary artery disease in patients with a permanent pacemaker. The prognostic value of pacemaker stress echocardiography has not been studied.

SUBJECTS AND METHODS

We studied 136 patients (mean age 64+/-12 years) with a permanent pacemaker who underwent pacemaker stress echocardiography for evaluation of coronary artery disease. All patients underwent pacemaker stress echocardiography by external programming (pacing heart rate up to ischemia or target heart rate).

RESULTS

Thirty-one patients (23%) had normal study results. Ischemia was detected in 75 patients (55%). During a mean follow-up of 3.5+/-2.4 years, 35 deaths (26%) (20 the result of cardiac causes) and 2 nonfatal myocardial infarctions (1%) occurred. The annual cardiac death rate was 1.3% in patients without ischemia and 4.6% in patients with ischemia (P=.01). The annual all-cause mortality rate was 3.1% in patients without ischemia and 7% in patients with ischemia (P=.004). The presence of ischemia during pacemaker stress echocardiography was the strongest independent predictor of cardiac death (hazard ratio 4.1, confidence interval 1.2-14.5) and all-cause mortality (hazard ratio 2.7, confidence interval 1.2-6.0) in a multivariable model.

CONCLUSION

Myocardial ischemia during pacemaker stress echocardiography is an independent predictor of cardiac death and all-cause mortality in patients with a permanent pacemaker.

Prognostic value of dobutamine stress myocardial contrast perfusion echocardiography

BACKGROUND

Myocardial perfusion (MP) imaging with real-time contrast echocardiography (RTCE) improves the sensitivity of dobutamine stress echocardiography for detecting coronary artery disease. Its prognostic value is unknown. We sought to determine the value of MP and wall motion (WM) analysis during dobutamine stress echocardiography in predicting the outcome of patients with known or suspected coronary artery disease.

METHODS AND RESULTS

We retrospectively studied 788 patients with RTCE during dobutamine stress echocardiography using intravenous commercially available contrast agents. The incremental prognostic value of MP imaging over clinical risk factors and other echocardiographic data was examined through the use of a log-likelihood test (Cox model). During a median follow-up of 20 months, 75 events (9.6%) occurred (58 deaths, 17 nonfatal myocardial infarctions). Abnormal MP had significant incremental value over clinical factors, resting ejection fraction, and WM responses in predicting events (P<0.001). By multivariate analysis, the independent predictors of death and nonfatal myocardial infarction were resting left ventricular ejection fraction <50% (relative risk [RR], 1.9; 95% CI, 1.2 to 3.2; P=0.01), hypercholesterolemia (RR, 0.5; 95% CI, 0.3 to 0.9; P=0.01), and abnormal MP (RR, 5.2; 95% CI, 3.0 to 9.0; P<0.0001). The 3-year event free survival was 95% for patients with normal WM and MP, 82% for normal WM and abnormal MP, and 68% for abnormal WM and MP.

CONCLUSIONS

MP imaging during dobutamine stress RTCE provides incremental prognostic information in patients with known or suspected coronary artery disease. Patients with normal MP have a better outcome than patients with normal WM.