Dean E. Smith

Long-term survival in patients presenting with type B acute aortic dissection: Insights from the international registry of acute aortic dissection

Background— Follow-up survival studies in patients with acute type B aortic dissection have been restricted to a small number of patients in single centers. We used data from a contemporary registry of acute type B aortic dissection to better understand factors associated with adverse long-term survival. Methods and Results— We examined 242 consecutive patients discharged alive with acute type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2003. Kaplan-Meier survival curves were constructed, and Cox proportional hazards analysis was performed to identify independent predictors of follow-up mortality. Three-year survival for patients treated medically, surgically, or with endovascular therapy was 77.6±6.6%, 82.8±18.9%, and 76.2±25.2%, respectively (median follow-up 2.3 years, log-rank P=0.61). Independent predictors of follow-up mortality included female gender (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.07 to 3.71; P=0.03), a history of prior aortic aneurysm (HR, 2.17; 95% CI, 1.03 to 4.59; P=0.04), a history of atherosclerosis (HR, 2.48; 95% CI, 1.32 to 4.66; P<0.01), in-hospital renal failure (HR, 2.55; 95% CI, 1.15 to 5.63; P=0.02), pleural effusion on chest radiograph (HR, 2.56; 95% CI, 1.18 to 5.58; P=0.02), and in-hospital hypotension/shock (HR, 12.5; 95% CI, 3.24 to 48.21; P<0.01). Conclusions— Contemporary follow-up mortality in patients who survive to hospital discharge with acute type B aortic dissection is high, approaching 1 in every 4 patients at 3 years. Current treatment and follow-up surveillance require further study to better understand and optimize care for patients with this complex disease.

Clinical Profiles and Outcomes of Acute Type B Aortic Dissection in the Current Era: Lessons From the International Registry of Aortic Dissection (IRAD)

Background—Clinical profiles and outcomes of patients with acute type B aortic dissection have not been evaluated in the current era. Methods and Results—Accordingly, we analyzed 384 patients (65±13 years, males 71%) with acute type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD). A majority of patients had hypertension and presented with acute chest/back pain. Only one-half showed abnormal findings on chest radiograph, and almost all patients had computerized tomography (CT), transesophageal echocardiography, magnetic resonance imaging (MRI), and/or aortogram to confirm the diagnosis. In-hospital mortality was 13% with most deaths occurring within the first week. Factors associated with increased in-hospital mortality on univariate analysis were hypotension/shock, widened mediastinum, periaortic hematoma, excessively dilated aorta (≥6 cm), in-hospital complications of coma/altered consciousness, mesenteric/limb ischemia, acute renal failure, and surgical management (all P <0.05). A risk prediction model with control for age and gender showed hypotension/shock (odds ratio [OR] 23.8, P <0.0001), absence of chest/back pain on presentation (OR 3.5, P =0.01), and branch vessel involvement (OR 2.9, P =0.02), collectively named ‘the deadly triad’ to be independent predictors of in-hospital death. Conclusions—Our study provides insight into current-day profiles and outcomes of acute type B aortic dissection. Factors associated with increased in-hospital mortality (“the deadly triad”) should be identified and taken into consideration for risk stratification and decision-making.

Acute Intramural Hematoma of the Aorta A Mystery in Evolution

Background—The definition, prevalence, outcomes, and appropriate treatment strategies for acute intramural hematoma (IMH) continue to be debated. Methods and Results—We studied 1010 patients with acute aortic syndromes who were enrolled in the International Registry of Aortic Dissection (IRAD) to delineate the prevalence, presentation, management, and outcomes of acute IMH by comparing these patients with those with classic aortic dissection (AD). Fifty-eight (5.7%) patients had IMH, and this cohort tended to be older (68.7 versus 61.7 years; P<0.001) and more likely to have distal aortic involvement (60.3% versus 35.3%; P<0.001) compared with 952 patients with AD. Patients with IMH described more severe initial pain than did those with AD but were less likely to have ischemic leg pain, pulse deficits, or aortic valve insufficiency; moreover, they required a longer time to diagnosis and more diagnostic tests. Overall mortality of IMH was similar to that of classic AD (20.7% versus 23.9%; P=0.57), as was mortality in patients with IMH of the descending aorta (8.3% versus 13.1%; P=0.60) and the ascending aorta (39.1% versus 29.9%; P=0.34) compared with AD. IMH limited to the aortic arch was seen in 7 patients, with no deaths, despite medical therapy in only 6 of the 7 individuals. Among the 51 patients whose initial diagnostic study showed IMH only, 8 (16%) progressed to AD on a serial imaging study. Conclusions—The IRAD data demonstrate a 5.7% prevalence of IMH in patients with acute aortic syndromes. Like classic AD, IMH is a highly lethal condition when it involves the ascending aorta and surgical therapy should be considered, but this condition is less critical when limited to the arch or descending aorta. Fully 16% of patients have evidence of evolution to dissection on serial imaging.

Gender-Related Differences in Acute Aortic Dissection

Background—Few data exist on gender-related differences in clinical presentation, diagnostic findings, management, and outcomes in acute aortic dissection (AAD). Methods and Results—Accordingly, we evaluated 1078 patients enrolled in the International Registry of Acute Aortic Dissection (IRAD) to assess differences in clinical features, management, and in-hospital outcomes between men and women. Of the patients enrolled in IRAD (32.1%) with AAD, 346 were women. Although less frequently affected by AAD (32.1% of AAD), women were significantly older and had more often presented later than men (P =0.008); symptoms of coma/altered mental status were more common, whereas pulse deficit was less common. Diagnostic imaging suggestive of rupture, ie, periaortic hematoma, and pleural or pericardial effusion were more commonly observed in women. In-hospital complications of hypotension and tamponade occurred with greater frequency in women, resulting in higher in-hospital mortality compared with men. After adjustment for age and hypertension, women with aortic dissection die more frequently than men (OR, 1.4, P =0.04), predominantly in the 66- to 75-year age group. Moreover, surgical outcome was worse in women than men (P =0.013); type A dissection in women was associated with a higher surgical mortality of 32% versus 22% in men despite similar delay, surgical technique, and hemodynamics. Conclusions—Our analysis provides insights into gender-related differences in AAD with regard to clinical characteristics, management, and outcomes; important diagnostic and therapeutic implications may help shed light on aortic dissection in women to improve their outcomes.

Chronobiological Patterns of Acute Aortic Dissection

Background—Chronobiological rhythms have been shown to influence the occurrence of a variety of cardiovascular disorders. However, the effects of the time of the day, the day of the week, or monthly/seasonal changes on acute aortic dissection (AAD) have not been well studied. Methods and Results—Accordingly, we evaluated 957 patients enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2000 (mean age 62±14 years, type A 61%). A &khgr;2 test for goodness of fit and partial Fourier analysis were used to evaluate nonuniformity and rhythmicity of AAD during circadian, weekly, and monthly periods. A significantly higher frequency of AAD occurred from 6:00 am to 12:00 noon compared with other time periods (12:00 noon to 6:00 pm, 6:00 pm to 12:00 midnight, and 12:00 midnight to 6:00 am;P <0.001 by &khgr;2 test). Fourier analysis showed a highly significant circadian variation (P <0.001) with a peak between 8:00 am and 9:00 am. Although no significant variation was found for the day of the week, the frequency of AAD was significantly higher during winter (P =0.008 versus other seasons by &khgr;2 test). Fourier analysis confirmed this monthly variation with a peak in January (P <0.001). Subgroup analysis identified a significant association for all subgroups with circadian rhythmicity. However, seasonal/monthly variations were observed only among patients aged <70 years, those with type B AAD, and those without hypertension or diabetes. Conclusions—Similar to other cardiovascular conditions, AAD exhibits significant circadian and seasonal/monthly variations. Our findings may have important implications for the prevention of AAD by tailoring treatment strategies to ensure maximal benefits during the vulnerable periods.

Acute type A aortic dissection in the elderly: clinical characteristics, management, and outcomes in the current era

OBJECTIVES We sought to evaluate the clinical characteristics, management, and outcomes of elderly patients with acute type A aortic dissection. BACKGROUND Few data exist on the clinical manifestations and outcomes of acute type A aortic dissection in an elderly patient cohort. METHODS We categorized 550 patients with type A aortic dissection enrolled in the International Registry of Acute Aortic Dissection into two age strata (<70 and >or=70 years) and compared their clinical features, management, and in-hospital events. RESULTS Thirty-two percent of patients with type A dissection were aged >or=70 years. Marfan syndrome was exclusively associated with dissection in the young, whereas hypertension, atherosclerosis and iatrogenic dissection predominated in older patients. Typical symptoms (abrupt onset of chest or back pain) and signs (aortic regurgitation murmur or pulse deficits) of dissection were less common among the elderly. Fewer elderly patients were managed surgically than younger patients (64% vs. 86%, p < 0.0001). Hypotension occurred more frequently (46% vs. 32%, p = 0.002) and focal neurologic deficits less frequently (18% vs. 26%, p = 0.04) among the elderly. In-hospital mortality was higher among older patients (43% vs. 28%, p = 0.0006). Logistic regression analysis identified age >or=70 years as an independent predictor of hospital death for acute type A aortic dissection (odds ratio 1.7, 95% confidence interval 1.1-2.8; p = 0.03). CONCLUSIONS Our study shows significant differences between older (age >or=70 years) and younger (age <70 years) patients with acute type A aortic dissection in their clinical characteristics, management, and hospital outcomes. Future research should evaluate strategies to improve outcomes in this high-risk elderly cohort.

Renal function-based contrast dosing to define safe limits of radiographic contrast media in patients undergoing percutaneous coronary interventions.

OBJECTIVES The aim of this study was to evaluate the association between calculated creatinine clearance (CCC)-based contrast dose and renal complications in patients undergoing percutaneous coronary interventions (PCI). BACKGROUND Excess volumes of contrast media are associated with renal complications in patients undergoing cardiac procedures. Because contrast media are excreted by the kidney, we hypothesized that a dose estimation on the basis of CCC would provide a simple strategy to define a safe dose of contrast media. METHODS We assessed the association between CCC-based contrast dose and the risk of contrast-induced nephropathy (CIN) and need for in-hospital dialysis in 58,957 patients undergoing PCI and enrolled in the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry from 2007 to 2008. Patients receiving dialysis at the time of the procedure were excluded. RESULTS The risk of CIN and nephropathy requiring dialysis (NRD) was directly associated with increasing contrast volume adjusted for renal function. The risk for CIN and NRD approached significance when the ratio of contrast dose/CCC exceeded 2 (adjusted odds ratio [OR] for CIN: 1.16, 95% confidence interval [CI]: 0.98 to 1.37, adjusted OR for NRD: 1.72, 95% CI: 0.9 to 3.27) and was dramatically elevated in patients exceeding a contrast to CCC ratio of 3 (adjusted OR for CIN: 1.46, 95% CI: 1.27 to 1.66, adjusted OR for NRD: 1.89, 95% CI: 1.21 to 2.94). CONCLUSIONS Our study supports the need for minimizing contrast dose in patients with renal dysfunction. A contrast dose on the basis of estimated renal function with a planned contrast volume restricted to less than thrice and preferably twice the CCC might be valuable in reducing the risk of CIN and NRD.

Association of a Continuous Quality Improvement Initiative With Practice and Outcome Variations of Contemporary Percutaneous Coronary Interventions

Background— The objective of this study was to evaluate the association of a continuous quality improvement program with practice and outcome variations of percutaneous coronary intervention (PCI). Methods and Results— Data on consecutive PCI were collected in a consortium of 5 hospitals; 3731 PCIs reflected care provided at baseline (January 1, 1998, to December 31, 1998), and 5901 PCIs reflected care provided after implementation of a continuous quality improvement intervention (January 1, 2002, to December 31, 2002). The intervention included feedback on outcomes, working group meetings, site visits, selection of quality indicators, and use of bedside tools for quality improvement and risk assessment. Postintervention data were compared with baseline and with 10 287 PCIs from 7 hospitals added to the consortium in 2002. Quality indicators included use of preprocedural aspirin or clopidogrel, use of glycoprotein IIb/IIIa receptor blockers and postprocedural heparin, and amount of contrast media per case. Outcomes selected included emergency CABG, contrast nephropathy, myocardial infarction, stroke, transfusion, and in-hospital death. Compared with baseline and the control group, the intervention group at follow-up had higher use of preprocedural aspirin and glycoprotein IIb/IIIa blockers, lower use of postprocedural heparin, and a lower amount of contrast media per case (P<0.05). These changes were associated with lower rates of transfusions, vascular complications, contrast nephropathy, stroke, transient ischemic attack, and combined end points (all P<0.05). Conclusions— Our nonrandomized, observational data suggest that implementation of a regional continuous quality improvement program appears to be associated with enhanced adherence to quality indicators and improved outcomes of PCI. A randomized clinical trial is needed to determine whether this is a “causal” or a “casual” relationship.

Usefulness of pulse deficit to predict in-hospital complications and mortality in patients with acute type A aortic dissection

Vascular compromise seen with pulse deficits is common in patients with type A dissection. However, patient characteristics and in-hospital outcomes associated with pulse deficits have not been evaluated. Accordingly, we studied 513 patients (mean age 62 +/- 14 years, 65% men) with acute type A aortic dissection enrolled in the International Registry of Acute Aortic Dissection. Pulse deficits, defined as decreased or absent carotid or peripheral pulses as noted by clinicians and later confirmed by diagnostic imaging, at surgery or at autopsy were noted in 154 patients (30%). Age <70 years, male gender, neurologic deficit(s), altered mental status, and hypotension, shock, or tamponade on admission were all significantly higher in patients with than without pulse deficits. The etiology of aortic dissection, clinical symptoms, and imaging findings were similar in the 2 groups. In-hospital complications (hypotension, coma, renal failure, and limb ischemia) and mortality (41% vs 25%, p = 0.0002) were significantly higher in patients with pulse deficit. Cox proportional-hazards regression analysis identified pulse deficit as an independent predictor of 5-day in-hospital mortality (risk ratio 2.73, 95% confidence interval 1.7 to 4.4; p <0.0001). Further, overall mortality rates increased with an increasing number of pulse deficits (p for trend <0.0001). Pulse deficits are common findings in patients with type A aortic dissection and identify those at high risk of in-hospital adverse events. This simple clinical sign should direct physicians to consider a diagnosis of aortic dissection in patients with acute chest pain, and should help identify a subgroup of patients who would benefit from more aggressive strategies.

Differences in Clinical Presentation, Management, and Outcomes of Acute Type A Aortic Dissection in Patients With and Without Previous Cardiac Surgery

Background—There are less data on the clinical and diagnostic imaging characteristics, management, and outcomes of patients with previous cardiac surgery (PCS) presenting with acute type A aortic dissection (AAD). Methods and Results—In 617 patients with AAD, we evaluated the differences in the clinical characteristics, management, and in-hospital outcomes of the cohorts with and without PCS. A history of PCS was present in 100 of 617 patients. Patients with PCS were more likely to be males (P=0.02), older (P=0.014), and to have a history of previous aortic dissection (P<0.001) or aneurysms (P<0.001). In contrast, PCS patients were less likely to have presenting chest pain (P<0.001). Cardiac tamponade was less common in PCS patients (P=0.007). Fewer AAD patients with PCS underwent surgical repair (P=0.001). Hospital mortality was not adversely influenced by PCS (odds ratio [OR], 1.46; 95% confidence interval [CI], 0.81 to 2.63), but a trend for increased death was seen in patients with previous aortic valve replacement (AVR) (OR, 2.31; 95% CI, 0.98 to 5.43). Age70 years or older, previous AVR, shock, and renal failure identified PCS patients at risk for death. Conclusions—Our study highlights differences in clinical characteristics, management, and outcomes of AAD patients with PCS. Importantly, PCS, with the exception of previous AVR, does not adversely influence early outcomes of AAD patients, including those undergoing surgical repair. However, because of otherwise dismal outcomes with medical management of AAD, our data indicate that a history of PCS (even that of previous AVR) should not preclude physicians from recommending surgical correction of type A aortic dissection in appropriate patients.