A user-friendly risk-score for predicting in-hospital cardiac arrest among patients admitted with suspected non ST-elevation acute coronary syndrome - The SAFER-score

AIM

To develop a simple risk-score model for predicting in-hospital cardiac arrest (CA) among patients hospitalized with suspected non-ST elevation acute coronary syndrome (NSTE-ACS).

METHODS

Using the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART), we identified patients (n=242 303) admitted with suspected NSTE-ACS between 2008 and 2014. Logistic regression was used to assess the association between 26 candidate variables and in-hospital CA. A risk-score model was developed and validated using a temporal cohort (n=126 073) comprising patients from SWEDEHEART between 2005 and 2007 and an external cohort (n=276 109) comprising patients from the Myocardial Ischaemia National Audit Project (MINAP) between 2008 and 2013.

RESULTS

The incidence of in-hospital CA for NSTE-ACS and non-ACS was lower in the SWEDEHEART-derivation cohort than in MINAP (1.3% and 0.5% vs. 2.3% and 2.3%). A seven point, five variable risk score (age ≥60 years (1 point), ST-T abnormalities (2 points), Killip Class >1 (1 point), heart rate <50 or ≥100bpm (1 point), and systolic blood pressure <100mmHg (2 points) was developed. Model discrimination was good in the derivation cohort (c-statistic 0.72) and temporal validation cohort (c-statistic 0.74), and calibration was reasonable with a tendency towards overestimation of risk with a higher sum of score points. External validation showed moderate discrimination (c-statistic 0.65) and calibration showed a general underestimation of predicted risk.

CONCLUSIONS

A simple points score containing five variables readily available on admission predicts in-hospital CA for patients with suspected NSTE-ACS.

Cardiac Troponins and Their Prognostic Importance in Patients with Suspected Acute Coronary Syndrome and Renal Dysfunction

BACKGROUND

Cardiac troponin (cTn) is important for risk assessment in patients with suspected acute coronary syndrome (ACS). cTn concentrations may, however, be affected by renal dysfunction, and the clinical importance of this interrelation is not well established. We investigated the association between cTnT and cTnI (measured with conventional assays and a more sensitive assay) with the estimated glomerular filtration rate (eGFR) and also assessed the ability of cTn to predict the 1-year all-cause mortality.

METHODS

This retrospective registry-based study used data from 309454 admissions to Swedish coronary care units. cTn associations with eGFR and mortality were assessed using different regression models and by calculating multivariable-adjusted c-statistics.

RESULTS

cTnT concentrations exhibited stronger associations with eGFR than cTnI concentrations (conventional cTnT assay: β = −0.113; more sensitive cTnT assay: β= −0.186; pooled conventional cTnI assays: β = −0.098). Overall, cTnT provided greater prognostic accuracy than cTnI. This was most evident in non-ACS patients with normal or mildly reduced eGFR when using the more sensitive assay. Despite higher mortality rates, no consistent increases in the c-statistics of cTn were seen with severely reduced eGFR irrespective of the presence of ACS or non-ACS.

CONCLUSIONS

cTnT concentrations exhibited stronger associations with reduced eGFR than cTnI concentrations in patients admitted because of suspected ACS. cTnT, particularly when measured using the more sensitive assay, also tended to be a stronger prognosticator. However, the relative significance of the obtained results must be considered in the context of the severity of renal dysfunction and whether ACS is present.

Risk factors for worsening renal function and their association with long-term mortality following transcatheter aortic valve implantation: data from the SWEDEHEART registry

BACKGROUND

The occurrence of persistent acute kidney injury (pAKI) following transcatheter aortic valve implantation (TAVI) has serious implications.

METHODS

There were 1540 patients undergoing and surviving TAVI included in the nationwide SWEDEHEART registry between 2008 and 2015. Creatinine was measured at baseline and discharge, and those with baseline estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m² or dialysis were excluded. pAKI was defined by and encompassing theValve Academic Research Consortium-2 (VARC-2) criteria: increase in serum creatinine concentration ≥26.5 μmol/L or increase by ≥50% (1.5×), or start of in-hospital dialysis until hospital discharge. Logistic regression analysis was used to find baseline factors associated with pAKI. Adjusted Cox regression analysis was used to assess the association of pAKI with mortality. Median follow-up was 1.8 years (IQR 0.7-3.0).

RESULTS

pAKI occurred in 6.1% (n=94) of the patients (71.3% male). These patients had higher creatinine level (117±50 vs 100±35 mmol/L, p<0.001), but similar baseline eGFR (59±21 vs 56±23 mL/min/1.73 m², p=0.18) and received higher contrast volume (129 mL ±89 vs 110 mL ±78, p=0.027). On multivariable logistic regression analysis, pAKI was predicted by eGFR (OR 0.88, 95% CI (0.79 to 0.98), p=0.019), male gender (OR 2.68, 95% CI (1.63 to 4.38), p<0.001) and apical access (OR 2.23, 95% CI (1.35 to 3.69), p=0.002), whereas contrast volume/10 mL (OR 1.02, 95% CI (1.00 to 1.05), p=0.052) did not reach statistical significance. Mortality at 1 year/end of follow-up was 10.4%/26.9%. pAKI was associated with a doubled risk of death (HR 2.04, 95% CI (1.49 to 2.81), p<0.001).

CONCLUSION

Persistent AKI after TAVI occurs in 6.1% and is associated with a doubled long-term mortality. Special efforts to avoid AKI should be taken, especially among vulnerable patients.

Comparison of the Chronic Kidney Disease Epidemiology Collaboration, the Modification of Diet in Renal Disease study and the Cockcroft-Gault equation in patients with heart failure

Background

It is unknown how the creatinine-based renal function estimations differ for dose adjustment cut-offs and risk prediction in patients with heart failure.

Method and results

The renal function was similar with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) (median 59 mL/min/1.73 m², IQR 42 to 77) and Modification of Diet in Renal Disease Study (MDRD) (59 mL/min/1.73 m², IQR 43 to 75) and slightly lower with the Cockcroft-Gault (CG) equation (57 mL/min, IQR 39 to 82). Across the commonly used renal function stages, the CKD-EPI and the MDRD classified patients into the same stage in 87.2% (kappa coefficient 0.83, p<0.001); the CKD-EPI and the CG equation agreed in 52.3% (kappa coefficient 0.39, p<0.001). Hence, a differing number of patients will receive dose adjustment depending on which formula is used as cut-off. The CG equation predicted worse prognosis better (c-statistics 0.740, 95% CI 0.734 to 0.746) than CKD-EPI (0.697, 95% CI 0.690 to 0.703, p<0.001) and MDRD (0.680, 95% CI 0.734 to 0.746). Using net reclassification improvement (NRI), the CG identified 12.8% more patients at higher risk of death as compared with the CKD-EPI equation.

Patients registered in the Swedish Heart Failure Registry (n= 40 736) with standardised creatinine values between 2000 and 2012 had their renal function estimated with the CKD-EPI, the MDRD and the CG. Agreement between the formulas was compared for categories. Prediction of death was assessed with c-statistics and with NRI.

Conclusion

The choice of renal function estimation formula has clinical implications and differing results at various cut-off levels. For prognosis, the CG predicts mortality better than the CKD-EPI and MDRD.

Time in Therapeutic Range and Outcomes After Warfarin Initiation in Newly Diagnosed Atrial Fibrillation Patients With Renal Dysfunction

Background

It is unknown whether renal dysfunction conveys poor anticoagulation control in warfarin‐treated patients with atrial fibrillation and whether poor anticoagulation control associates with the risk of adverse outcomes in these patients.

Methods and Results

This was an observational study from the Stockholm CREatinine Measurements (SCREAM) cohort including all newly diagnosed atrial fibrillation patients initiating treatment with warfarin (n=7738) in Stockholm, Sweden, between 2006 and 2011. Estimated glomerular filtration rate (eGFR; mL/min per 1.73 m²) was calculated from serum creatinine. Time‐in‐therapeutic range (TTR) was assessed from international normalized ratio (INR) measurements up to warfarin cessation, adverse event, or end of follow‐up (2 years). Adverse events considered a composite of intracranial hemorrhage, ischemic stroke, myocardial infarction, or death. During median 254 days, TTR was 83%, based on median 21 INR measurements per patient. TTR was 70% among patients with eGFR <30, around 10% lower than in those with normal renal function. During observation, adverse events occurred in 4.0% of patients, and those with TTR ≤75% were at higher adverse event risk. This was independent of patient characteristics, comorbidities, number of INR tests, days exposed to warfarin, and, notably, independent of eGFR: adjusted odds ratio (OR) 1.84 (95% CI, 1.41–2.40) for TTR 75% to 60% and adjusted OR 2.09 (1.59–2.74) for TTR <60%. No interaction was observed between eGFR and TTR in association to adverse events (P=0.2).

Conclusion

Severe chronic kidney disease (eGFR <30) patients with atrial fibrillation have worse INR control while on warfarin. An optimal TTR (>75%) is associated with lower risk of adverse events, independently of underlying renal function.

Long-term versus short-term dual antiplatelet therapy was similarly associated with a lower risk of death, stroke, or infarction in patients with acute coronary syndrome regardless of underlying kidney disease

Scarce and conflicting evidence exists on whether clopidogrel is effective and whether dual antiplatelet treatment (DAPT) is safe in patients with acute coronary syndrome and chronic kidney disease (CKD). To study this, we performed an observational, prospective, multicenter cohort study of 36,001 patients of the SWEDEHEART registry. The exposure was DAPT prolonged after 3 months versus DAPT stopped at 3 months in consecutive patients with acute coronary syndrome and known serum creatinine. DAPT duration with clopidogrel and aspirin was assessed by dispensed tablets. CKD stages were classified according to estimated glomerular filtration rate (eGFR). Study outcomes were 1) the composite of death, myocardial infarction, or ischemic stroke; 2) bleeding; or 3) the aggregate of these two outcomes within day 111 and 365 from discharge. A longer DAPT duration, as compared with 3-month DAPT, was associated with lower hazard ratios for outcome one in each CKD stratum (eGFR over 60, adjusted hazard ratio [95% confidence interval] 0.76 [0.67-0.85]; eGFR 60 and less, 0.84 [0.73-0.96], of which eGFR between 45 and 60, 0.85 [0.70-1.05], eGFR between 30 and 45, 0.78 [0.62-0.97]; eGFR 30 and less ml/min/1.73 m², 0.93 [0.70-1.24]. Bleeding (outcome 2) was in general more common in the longer DAPT group of each aforementioned CKD stratum. Aggregated outcome analysis (outcome 3) similarly favored longer DAPT in each stratum. There was no interaction between DAPT duration and CKD strata for any of the study outcomes. Thus, a prolonged as compared with three-month DAPT was similarly associated with a lower risk of death, stroke, or reinfarction regardless of underlying CKD.

Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Myocardial Infarction Patients With Renal Dysfunction

BACKGROUND

There is no consensus whether angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) should be used for secondary prevention in all or in only high-risk patients after an acute myocardial infarction (AMI).

OBJECTIVES

This study sought to investigate whether ACEI/ARB treatment after AMI is associated with better outcomes across different risk profiles, including the entire spectrum of estimated glomerular filtration rates.

METHODS

This study evaluated discharge and continuous follow-up data on ACEI/ARB use among AMI survivors (2006 to 2009) included in a large Swedish registry. The association between ACEI/ARB treatment and outcomes (mortality, myocardial infarction, stroke, and acute kidney injury [AKI]) was studied using Cox proportional hazards models (intention-to-treat and as treated).

RESULTS

In total, 45,697 patients (71%) were treated with ACEI/ARB. The 3-year mortality was 19.8% (17.4% of ACEI/ARB users and 25.4% of nonusers). In adjusted analysis, significantly better survival was observed for patients treated with ACEI/ARB (3-year hazard ratio: 0.80; 95% confidence interval: 0.77 to 0.83). The survival benefit was consistent through all kidney function strata, including dialysis patients. Overall, those treated with ACEI/ARB also had lower 3-year risk for myocardial infarction (hazard ratio: 0.91; 95% confidence interval: 0.87 to 0.95), whereas treatment had no significant effect on stroke risk. The crude risk for AKI was in general low (2.5% and 2.0% for treated and nontreated, respectively) and similar across estimated glomerular filtration rate categories but was significantly higher with ACEI/ARB treatment. However, the composite outcome of AKI and mortality favored ACEI/ARB treatment.

CONCLUSIONS

Treatment with ACEI/ARB after AMI was associated with improved long-term survival, regardless of underlying renal function, and was accompanied by low rates of adverse renal events.

Prevalence and prognostic impact of kidney disease on heart failure patients

Objectives

The aim was to determine the prevalence of different degrees of kidney dysfunction and to examine their association with short-term and long-term outcomes in a large unselected contemporary heart failure population and some of its subgroups. We examined to what extent the different cardiac conditions and their severity contribute to the prognostic value of kidney dysfunction in heart failure.

Design

We studied 47 716 patients in the Swedish Heart Failure Registry. Patients were divided into five renal function strata based on estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration equation. The adjusted association between kidney function and outcome was examined by Cox regression.

Results

51% of the patients had eGFR <60 mL/min/1.73 m² and 11% had eGFR <30. There was increasing mortality with decreasing kidney function regardless of age, presence of diabetes, New York Heart Association NYHA class, duration of heart failure and haemoglobin levels. The risk HR (95% CI) persisted after adjusting for differences in baseline characteristics, severity of heart disease, and medical treatment: eGFR 60–89: 0.86 (0.79 to 0.95); eGFR 30–59: 1.13 (1.03 to 1.24); eGFR 15–29: 1.85 (1.67 to 2.07); and eGFR <15: 2.96 ([2.53 to –3.47)], compared with eGFR ≥90.

Conclusions

Kidney dysfunction is common and strongly associated with short-term and long-term outcomes in patients with heart failure. This strong association was evident in all age groups, regardless of NYHA class, duration of heart failure, haemoglobin level, and presence/absence of diabetes mellitus. After adjusting for differences in baseline data, aetiology and severity of heart disease and treatment, the strong association remained.

Prevalence and prognostic impact of chronic kidney disease in STEMI from a gender perspective: data from the SWEDEHEART register, a large Swedish prospective cohort

OBJECTIVES

Gender differences in prevalence and prognostic impact of chronic kidney disease (CKD) in ST segment elevation myocardial infarction (STEMI) have been poorly evaluated. In STEMI, female gender has been independently associated with an increased risk of mortality. CKD has been found to be an important prognostic marker in myocardial infarction. The aim of this study was to evaluate gender differences in prevalence and prognostic impact of CKD on short-term and long-term mortality.

DESIGN

Prospective observational cohort study.

SETTING

The national quality register SWEDEHEART was used. In the beginning of the study period, 94% of the Swedish coronary care units contributed data to the register, which subsequently increased to 100%. The glomerular filtration rate was estimated (eGFR) according to Modification of Diet in Renal Disease Study (MDRD) and Cockcroft-Gault (CG).

PARTICIPANTS

All patients with STEMI registered in SWEDEHEART from the years 2003-2009 were included (37,991 patients, 66% men).

MAIN RESULTS

Women had 1.6 (MDRD) to 2.2 (CG) times higher multivariable adjusted risk of CKD. Half of the women had CKD according to CG. CKD was associated with 2-2.5 times higher risk of in-hospital mortality and approximately 1.5 times higher risk of long-term mortality in both genders. Each 10 mL/min decline of eGFR was associated with an increased risk of in-hospital and long-term mortality (22-33% and 9-16%, respectively) and this did not vary significantly by gender. Both in-hospital and long-term mortality were doubled in women. After multivariable adjustment including eGFR, there was no longer any gender difference in early outcome and the long-term outcome was better in women.

CONCLUSIONS

Among patients with STEMI, female gender was independently associated with CKD. Reduced eGFR was a strong independent risk factor for short-term and long-term mortality without a significant gender difference in prognostic impact and seems to be an important reason why women have higher mortality than men with STEMI.

Association between the use of fondaparinux vs low-molecular-weight heparin and clinical outcomes in patients with non-ST-segment elevation myocardial infarction

IMPORTANCE

Fondaparinux was associated with reduced major bleeding events and improved survival compared with low-molecular-weight heparin (LMWH) in a large randomized clinical trial involving patients with non-ST-segment elevation myocardial infarction (NSTEMI). Large-scale experience of the use of fondaparinux vs LMWH in a nontrial setting is lacking.

OBJECTIVE

To study the association between the use of fondaparinux vs LMWH and outcomes in patients with NSTEMI in Sweden.

DESIGN, SETTING, AND PATIENTS

Prospective multicenter cohort study from the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry involving 40,616 consecutive patients with NSTEMI who received fondaparinux or LMWH between September 1, 2006, through June 30, 2010, with the last follow-up on December 31, 2010.

EXPOSURES

In-hospital treatment with fondaparinux or LMWH during the hospital stay.

MAIN OUTCOMES AND MEASURES

In-hospital severe bleeding events and death and 30- and 180-day death, MI, stroke, and major bleeding events. Logistic regression models adjusted for calendar time, admitting hospital, baseline characteristics, and in-hospital revascularization.

RESULTS

In total, 14,791 patients (36.4%) were treated with fondaparinux and 25,825 (63.6%) with LMWH. One hundred sixty-five patients (1.1%) in the fondaparinux group vs 461 patients (1.8%) in the LMWH group experienced in-hospital bleeding events (adjusted odds ratio [OR], 0.54; 95% CI, 0.42-0.70). A total of 394 patients (2.7%) in the fondaparinux group died while in the hospital vs 1022 (4.0%) in the LMWH group (adjusted OR, 0.75; 95% CI, 0.63-0.89). The differences in major bleeding events and mortality between the 2 treatments were similar at 30 and 180 days. There were no significant differences in the number of recurrent MI and stroke events at 30 or 180 days among the 2 treatment groups.

CONCLUSIONS AND RELEVANCE

In routine clinical care of patients with NSTEMI, fondaparinux was associated with lower odds than LMWH of major bleeding events and death both in-hospital and up to 180 days afterward.

Warfarin, kidney dysfunction, and outcomes following acute myocardial infarction in patients with atrial fibrillation

IMPORTANCE

Conflicting evidence exists regarding the association between warfarin treatment, death, and ischemic stroke incidence in patients with advanced chronic kidney disease (CKD) and atrial fibrillation.

OBJECTIVE

To study outcomes associated with warfarin treatment in relation to kidney function among patients with established cardiovascular disease and atrial fibrillation.

DESIGN, SETTING, AND PARTICIPANTS

Observational, prospective, multicenter cohort study from the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry (2003-2010), which includes all Swedish hospitals that provide care for acute cardiac diseases. Participants included consecutive survivors of an acute myocardial infarction (MI) with atrial fibrillation and known serum creatinine (N = 24,317), including 21.8% who were prescribed warfarin at discharge. Chronic kidney disease stages were classified according to estimated glomerular filtration rate (eGFR).

MAIN OUTCOMES AND MEASURES

(1) Composite end point analysis of death, readmission due to MI, or ischemic stroke; (2) bleeding (composite of readmission due to hemorrhagic stroke, gastrointestinal bleeding, bleeding causing anemia, and others); or (3) the aggregate of these 2 outcomes within 1 year from discharge date.

RESULTS

A total of 5292 patients (21.8%) were treated with warfarin at discharge, and 51.7% had manifest CKD (eGFR <60 mL/min/1.73 m2 [eGFR<60]). Compared with no warfarin use, warfarin was associated with a lower risk of the first composite outcome (n = 9002 events) in each CKD stratum for event rates per 100 person-years: eGFR>60 event rate, 28.0 for warfarin vs 36.1 for no warfarin; adjusted hazard ratio (HR), 0.73 (95% CI, 0.65 to 0.81); eGFR>30-60: event rate, 48.5 for warfarin vs 63.8 for no warfarin; HR, 0.73 (95% CI, 0.66 to 0.80); eGFR>15-30: event rate, 84.3 for warfarin vs 110.1 for no warfarin; HR, 0.84 (95% CI, 0.70-1.02); eGFR≤15: event rate, 83.2 for warfarin vs 128.3 for no warfarin; HR, 0.57 (95% CI, 0.37-0.86). The risk of bleeding (n = 1202 events) was not significantly higher in patients treated with warfarin in any CKD stratum for event rates per 100 person-years: eGFR>60 event rate, 5.0 for warfarin vs 4.8 for no warfarin; HR, 1.10 (95% CI, 0.86-1.41); eGFR>30-60 event rate, 6.8 for warfarin vs 6.3 for no warfarin; HR, 1.04 (95% CI, 0.81-1.33); eGFR>15-30 event rate, 9.3 for warfarin vs 10.4 for no warfarin; HR, 0.82 (95% CI, 0.48-1.39); eGFR≤15 event rate, 9.1 for warfarin vs 13.5 for no warfarin; HR, 0.52 (95% CI, 0.16-1.65). Warfarin use in each CKD stratum was associated with lower hazards of the aggregate outcome (n = 9592 events) for event rates per 100 person-years: eGFR>60 event rate, 32.1 for warfarin vs 40.0 for no warfarin; HR, 0.76 (95% CI, 0.69-0.84); eGFR>30-60 event rate, 53.6 for warfarin vs 69.0 for no warfarin; HR, 0.75 (95% CI, 0.68-0.82); eGFR>15-30 event rate, 90.2 for warfarin vs 117.7 for no warfarin; HR, 0.82 (95% CI, 0.68-0.99); eGFR≤15 event rate, 86.2 for warfarin vs 138.2 for no warfarin; HR, 0.55 (95% CI, 0.37-0.83).

CONCLUSIONS AND RELEVANCE

Warfarin treatment was associated with a lower 1-year risk for the composite outcome of death, MI, and ischemic stroke without a higher risk of bleeding in consecutive acute MI patients with atrial fibrillation. This association was not related to the severity of concurrent CKD.