Exhibit 99.43 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-M KEY PERFORMANCE FACTORS September 30, 2000 Expected B Maturity 11/15/2004 Blended Coupon 6.6788% Excess Protection Level 3 Month Average 5.81% September, 2000 5.77% August, 2000 5.62% July, 2000 6.04% Cash Yield19.26% Investor Charge Offs 4.49% Base Rate 8.99% Over 30 Day Delinquency 4.99% Seller's Interest 8.50% Total Payment Rate13.85% Total Principal Balance$54,293,652,263.17 Investor Participation Amount$500,000,000.00 Seller Participation Amount$4,612,451,744.68