Coronary flow reserve is impaired in patients with aortic valve calcification

Prognostic significance of aortic valve calcification in relation to coronary artery calcification for cardiovascular diseases

AIMS

Both coronary artery calcification (CAC) and aortic valve calcification (AVC) are strongly associated with cardiovascular diseases (CVDs), but data about the prognostic significance of multiple cardiovascular calcifications are limited. We aim to investigate the interaction relationship between AVC and CAC for major events.

METHODS AND RESULTS

We included 6695 participants from the Multi-Ethnic Study of Atherosclerosis at baseline and divided them into four groups: (i) no AVC or CAC; (ii) only AVC; (iii) only CAC; and (iv) with CAC and CAC. The Cox regression model and the Kaplan-Meier method were used to analyse CVD outcomes. We evaluated the interaction between AVC and CAC and their added predictive value based on the pooled cohort equations (PCEs). Subgroup analyses were also explored. Among 6695 participants (mean age 62.2 ± 10.2 years, 47.2% male), after follow-up, 943 cases (14.1%) of CVD and 1274 cases (19.0%) of all-cause death occurred. For participants with both AVC and CAC, the risk of CVD significantly increased [hazard ratio = 3.43 (2.69-4.37), P < 0.001], even higher than the sum of the ones with only AVC and only CAC. This trend remained the same for all-cause death and among subgroup analyses. The addictive interaction was statistically significant (P < 0.001). When AVC and CAC were added, the predictive value of PCEs increased.

CONCLUSION

Our results indicated a synergistic interaction between valve calcification and coronary calcification in CVDs. Management for both AVC and CAC may bring health co-benefits in preventing poor outcomes.

Aortic valve sclerosis and subclinical LV dysfunction in the general population with normal LV geometry

AIMS

Aortic valve sclerosis (AVS) without hemodynamically significant obstruction is related to cardiovascular morbidity and mortality independent of left ventricular (LV) hypertrophy, although the underlying mechanisms remain unknown. This study investigated the prevalence of AVS and its association with subclinical LV systolic and diastolic dysfunction in individuals with normal LV geometry free of cardiovascular disease.

METHODS

We examined 962 participants with normal LV geometry and free from significant AV stenosis who underwent standard and speckle-tracking echocardiography. AVS was categorized into 4 groups as follows: no AVS, AV thickening, calcification on one leaflet and calcification on ≥2 leaflets.

RESULTS

Among the 962 participants, 767 (79.7%) individuals were classified as no AVS, 74 (7.7%) as AV thickening, 87 (9.0%) as calcification on one leaflet, and 34 (3.5%) as calcification on ≥2 leaflets. The prevalence of subclinical LV diastolic dysfunction (E/e' ratio ≥13) and systolic dysfunction (LV global longitudinal strain (GLS) > -17.0% for men and > -18.0% for women) were greater in AVS groups than those in no AVS group. Subclinical LV diastolic impairment was evident from AV thickening and systolic dysfunction was observed at AV calcification. Multivariable logistic regression analysis demonstrated that AV thickening as well as calcification were independently associated with subclinical LV diastolic impairment (all p < 0.05), while only AV calcification on ≥2 leaflets conferred significant increased risk of impaired LVGLS.

CONCLUSIONS

AVS was observed in approximately 20% individuals without cardiac disease and was associated with subclinical LV diastolic and systolic function even in the absence of LV morphological change.

Aortic valve calcium is associated with left ventricular diastolic function in patients without evidence of ischaemic heart disease: assessment by gated single-photon emission computed tomography

BACKGROUND

Several studies have shown that aortic valve calcium (AVC) is associated with cardiovascular events. Furthermore, the extent of AVC is associated with adverse prognosis even in patients without significant aortic stenosis. We investigated the relationship between AVC and left ventricular (LV) diastolic parameters determined by gated single-photon emission computed tomography (SPECT) in patients with no evidence of ischaemic heart disease.

METHODS

This study included 157 patients with no evidence of ischaemic heart disease who underwent both coronary computed tomography and gated SPECT. The AVC scores were calculated by the Agatston method, and peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were determined as LV diastolic parameters.

RESULTS

There were 93 (59%) and 64 (41%) patients with and without AVC, respectively, and the AVC scores ranged from 0 to 1251. There was no significant difference in LV end-diastolic volume (EDV) (60 ± 18 vs 62 ± 25 mL, p = 0.52) or LV ejection fraction (67% ± 10% vs 66% ± 8%, p = 0.60) between the two groups. Patients with AVC had lower PFR (2.2 ± 0.5 vs 2.4 ± 0.5 EDV/s, p = 0.002) and 1/3 MFR (1.3 ± 0.3 vs 1.5 ± 0.4 EDV/s, p = 0.003) than those without AVC. Multivariate linear regression analysis showed that ln(AVC score + 1) was significantly associated with PFR and 1/3 MFR.

CONCLUSION

In patients without evidence of ischaemic heart disease, the extent of AVC was inversely correlated with gated SPECT-derived parameters of LV diastolic function.

Pathophysiological coronary and microcirculatory flow alterations in aortic stenosis

Regulation of coronary blood flow is maintained through a delicate balance of ventriculoarterial and neurohumoral mechanisms. The aortic valve is integral to the functions of these systems, and disease states that compromise aortic valve integrity have the potential to seriously disrupt coronary blood flow. Aortic stenosis (AS) is the most common cause of valvular heart disease requiring medical intervention, and the prevalence and associated socio-economic burden of AS are set to increase with population ageing. Valvular stenosis precipitates a cascade of structural, microcirculatory, and neurohumoral changes, which all lead to impairment of coronary flow reserve and myocardial ischaemia even in the absence of notable coronary stenosis. Coronary physiology can potentially be normalized through interventions that relieve severe AS, but normality is often not immediately achievable and probably requires continued adaptation. Finally, the physiological assessment of coronary artery disease in patients with AS represents an ongoing challenge, as the invasive physiological measures used in current cardiology practice are yet to be validated in this population. This Review discusses the key concepts of coronary pathophysiology in patients with AS through presentation of contemporary basic science and data from animal and human studies.

[Coronary microvascular dysfunction and aortic stenosis: an update]

The coronary microcirculatory impairment is a key feature of the pathophysiology of aortic stenosis (AS), the most operated valvular disease over the world. Several studies showed this coronary microcirculatory impairment in AS, using different tools and protocols, in various patient population of AS. This article will review the impairment of the coronary microcirculation in AS underlining its multifactorial origin, its functional part related to the hemodynamic consequences of AS, its complex relationship with left ventricular hypertrophy, and its potential diagnostic and prognostic value.

Prognostic value of echocardiographic-derived calcium index in coronary artery disease diagnosed by 64-multidetector computed tomography

PURPOSE

To determine whether echocardiographic calcium index (ECI) calculated using transthoracic echocardiography (TTE) predicts coronary ischemic events. We also wished to determine coronary artery calcium score (CACS), the presence of obstructive coronary artery disease (CAD) and plaque composition, all of which were assessed by multidetector computed tomography (MDCT).

METHODS

We carried out a prospective cohort study of 82 consecutive outpatients with chest pain and low-moderate risk of CAD, referred for noninvasive coronariography by MDCT. ECI was blindly assessed by TTE and correlated with subsequent cardiovascular events during a follow up period of 36 months.

RESULTS

ECI values of ≥7 had a sensitivity of 77.3%, a specificity of 90%, positive predictive value of 73.9%, and negative predictive value of 91.5% with respect to future coronary ischemic events. In addition, patients with ECI ≥ 7 showed a greater presence of severe calcified and obstructive CAD and a linear increase of obstructed vessels and mixed and calcified plaques, with a linear trend according to ECI values.

CONCLUSION

ECI values of ≥7 determine poor CAD prognosis in relation to ischemic events. Furthermore, ECI ≥ 7 may serve as a marker of content of coronary artery calcium, intraluminal obstruction, and plaque composition. Therefore, ECI seems to provide prognostic information as well as information about the characteristics of the plaque of atheroma.

[Functional vascular alterations associated with aortic valve stenosis]

Degenerative changes, atherosclerotic process and calcification of valvular leaflets are mostly responsible for valvular aortic valve stenosis, but congenital bicuspid aortic valve and rheumatic fever in history are also known predisposing factors. Aortic valve stenosis is frequently associated with different functional vascular alterations. The aim of this review is to demonstrate these vascular alterations evaluated by non-invasive methods and underlying physiologic and pathophysiologic processes.

Usefulness of echocardiographic assessment of cardiac and ascending aorta calcific deposits to predict coronary artery calcium and presence and severity of obstructive coronary artery disease

The presence of cardiac and aortic calcific deposits has been related to coronary artery disease (CAD) and cardiovascular events. The present study aimed to evaluate whether comprehensive echocardiographic assessment of cardiac and ascending aorta calcific deposits could predict coronary calcium and obstructive CAD. A total of 140 outpatients (age 61 +/- 11 years; 90 men) without a history of CAD were studied. Aortic valve sclerosis and mitral annular, papillary muscle, and ascending aorta calcific deposits were assessed using echocardiography and semiquantified using an echocardiography-derived calcium score (ECS) ranging from 0 (no calcium visible) to 8 (severe calcific deposits). Coronary calcium scoring and noninvasive coronary angiography were performed using multislice computed tomography. Angiograms showing atherosclerosis were classified as having obstructive (> or =50% luminal narrowing) CAD or not. The relation between ECS and multislice computed tomographic findings was explored using multivariate and receiver-operator characteristic curve analyses. Only ECS was associated with coronary calcium score >400 (odds ratio [OR] 3.6, 95% confidence interval [CI] 2.4 to 5.5, p <0.001). Similarly, only ECS (OR 1.8, 95% CI 1.4 to 2.4, p <0.001) and pretest likelihood of CAD (OR 1.7, 95% CI 1.0 to 2.8, p = 0.04) were associated with obstructive CAD. ECS > or =3 had high sensitivity and specificity in identifying patients with coronary calcium score >400 (87% for both) and obstructive CAD (74% and 82%, respectively). In conclusion, echocardiographic assessment of cardiac and ascending aorta calcium may allow detection of patients with extensive calcified coronary arterial atherosclerotic plaques.